Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 2676 insertions, 0 deletions

diff --git a/kernel/drivers/isdn/gigaset/bas-gigaset.c b/kernel/drivers/isdn/gigaset/bas-gigaset.c
new file mode 100644
index 000000000..aecec6d32
--- /dev/null
+++ b/kernel/drivers/isdn/gigaset/bas-gigaset.c
@@ -0,0 +1,2676 @@
+/*
+ * USB driver for Gigaset 307x base via direct USB connection.
+ *
+ * Copyright (c) 2001 by Hansjoerg Lipp <hjlipp@web.de>,
+ *                       Tilman Schmidt <tilman@imap.cc>,
+ *                       Stefan Eilers.
+ *
+ * =====================================================================
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License as
+ *	published by the Free Software Foundation; either version 2 of
+ *	the License, or (at your option) any later version.
+ * =====================================================================
+ */
+
+#include "gigaset.h"
+#include <linux/usb.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+
+/* Version Information */
+#define DRIVER_AUTHOR "Tilman Schmidt <tilman@imap.cc>, Hansjoerg Lipp <hjlipp@web.de>, Stefan Eilers"
+#define DRIVER_DESC "USB Driver for Gigaset 307x"
+
+
+/* Module parameters */
+
+static int startmode = SM_ISDN;
+static int cidmode = 1;
+
+module_param(startmode, int, S_IRUGO);
+module_param(cidmode, int, S_IRUGO);
+MODULE_PARM_DESC(startmode, "start in isdn4linux mode");
+MODULE_PARM_DESC(cidmode, "Call-ID mode");
+
+#define GIGASET_MINORS     1
+#define GIGASET_MINOR      16
+#define GIGASET_MODULENAME "bas_gigaset"
+#define GIGASET_DEVNAME    "ttyGB"
+
+/* length limit according to Siemens 3070usb-protokoll.doc ch. 2.1 */
+#define IF_WRITEBUF 264
+
+/* interrupt pipe message size according to ibid. ch. 2.2 */
+#define IP_MSGSIZE 3
+
+/* Values for the Gigaset 307x */
+#define USB_GIGA_VENDOR_ID      0x0681
+#define USB_3070_PRODUCT_ID     0x0001
+#define USB_3075_PRODUCT_ID     0x0002
+#define USB_SX303_PRODUCT_ID    0x0021
+#define USB_SX353_PRODUCT_ID    0x0022
+
+/* table of devices that work with this driver */
+static const struct usb_device_id gigaset_table[] = {
+	{ USB_DEVICE(USB_GIGA_VENDOR_ID, USB_3070_PRODUCT_ID) },
+	{ USB_DEVICE(USB_GIGA_VENDOR_ID, USB_3075_PRODUCT_ID) },
+	{ USB_DEVICE(USB_GIGA_VENDOR_ID, USB_SX303_PRODUCT_ID) },
+	{ USB_DEVICE(USB_GIGA_VENDOR_ID, USB_SX353_PRODUCT_ID) },
+	{ } /* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, gigaset_table);
+
+/*======================= local function prototypes ==========================*/
+
+/* function called if a new device belonging to this driver is connected */
+static int gigaset_probe(struct usb_interface *interface,
+			 const struct usb_device_id *id);
+
+/* Function will be called if the device is unplugged */
+static void gigaset_disconnect(struct usb_interface *interface);
+
+/* functions called before/after suspend */
+static int gigaset_suspend(struct usb_interface *intf, pm_message_t message);
+static int gigaset_resume(struct usb_interface *intf);
+
+/* functions called before/after device reset */
+static int gigaset_pre_reset(struct usb_interface *intf);
+static int gigaset_post_reset(struct usb_interface *intf);
+
+static int atread_submit(struct cardstate *, int);
+static void stopurbs(struct bas_bc_state *);
+static int req_submit(struct bc_state *, int, int, int);
+static int atwrite_submit(struct cardstate *, unsigned char *, int);
+static int start_cbsend(struct cardstate *);
+
+/*============================================================================*/
+
+struct bas_cardstate {
+	struct usb_device	*udev;		/* USB device pointer */
+	struct usb_interface	*interface;	/* interface for this device */
+	unsigned char		minor;		/* starting minor number */
+
+	struct urb		*urb_ctrl;	/* control pipe default URB */
+	struct usb_ctrlrequest	dr_ctrl;
+	struct timer_list	timer_ctrl;	/* control request timeout */
+	int			retry_ctrl;
+
+	struct timer_list	timer_atrdy;	/* AT command ready timeout */
+	struct urb		*urb_cmd_out;	/* for sending AT commands */
+	struct usb_ctrlrequest	dr_cmd_out;
+	int			retry_cmd_out;
+
+	struct urb		*urb_cmd_in;	/* for receiving AT replies */
+	struct usb_ctrlrequest	dr_cmd_in;
+	struct timer_list	timer_cmd_in;	/* receive request timeout */
+	unsigned char		*rcvbuf;	/* AT reply receive buffer */
+
+	struct urb		*urb_int_in;	/* URB for interrupt pipe */
+	unsigned char		*int_in_buf;
+	struct work_struct	int_in_wq;	/* for usb_clear_halt() */
+	struct timer_list	timer_int_in;	/* int read retry delay */
+	int			retry_int_in;
+
+	spinlock_t		lock;		/* locks all following */
+	int			basstate;	/* bitmap (BS_*) */
+	int			pending;	/* uncompleted base request */
+	wait_queue_head_t	waitqueue;
+	int			rcvbuf_size;	/* size of AT receive buffer */
+						/* 0: no receive in progress */
+	int			retry_cmd_in;	/* receive req retry count */
+};
+
+/* status of direct USB connection to 307x base (bits in basstate) */
+#define BS_ATOPEN	0x001	/* AT channel open */
+#define BS_B1OPEN	0x002	/* B channel 1 open */
+#define BS_B2OPEN	0x004	/* B channel 2 open */
+#define BS_ATREADY	0x008	/* base ready for AT command */
+#define BS_INIT		0x010	/* base has signalled INIT_OK */
+#define BS_ATTIMER	0x020	/* waiting for HD_READY_SEND_ATDATA */
+#define BS_ATRDPEND	0x040	/* urb_cmd_in in use */
+#define BS_ATWRPEND	0x080	/* urb_cmd_out in use */
+#define BS_SUSPEND	0x100	/* USB port suspended */
+#define BS_RESETTING	0x200	/* waiting for HD_RESET_INTERRUPT_PIPE_ACK */
+
+
+static struct gigaset_driver *driver;
+
+/* usb specific object needed to register this driver with the usb subsystem */
+static struct usb_driver gigaset_usb_driver = {
+	.name =         GIGASET_MODULENAME,
+	.probe =        gigaset_probe,
+	.disconnect =   gigaset_disconnect,
+	.id_table =     gigaset_table,
+	.suspend =	gigaset_suspend,
+	.resume =	gigaset_resume,
+	.reset_resume =	gigaset_post_reset,
+	.pre_reset =	gigaset_pre_reset,
+	.post_reset =	gigaset_post_reset,
+	.disable_hub_initiated_lpm = 1,
+};
+
+/* get message text for usb_submit_urb return code
+ */
+static char *get_usb_rcmsg(int rc)
+{
+	static char unkmsg[28];
+
+	switch (rc) {
+	case 0:
+		return "success";
+	case -ENOMEM:
+		return "out of memory";
+	case -ENODEV:
+		return "device not present";
+	case -ENOENT:
+		return "endpoint not present";
+	case -ENXIO:
+		return "URB type not supported";
+	case -EINVAL:
+		return "invalid argument";
+	case -EAGAIN:
+		return "start frame too early or too much scheduled";
+	case -EFBIG:
+		return "too many isoc frames requested";
+	case -EPIPE:
+		return "endpoint stalled";
+	case -EMSGSIZE:
+		return "invalid packet size";
+	case -ENOSPC:
+		return "would overcommit USB bandwidth";
+	case -ESHUTDOWN:
+		return "device shut down";
+	case -EPERM:
+		return "reject flag set";
+	case -EHOSTUNREACH:
+		return "device suspended";
+	default:
+		snprintf(unkmsg, sizeof(unkmsg), "unknown error %d", rc);
+		return unkmsg;
+	}
+}
+
+/* get message text for USB status code
+ */
+static char *get_usb_statmsg(int status)
+{
+	static char unkmsg[28];
+
+	switch (status) {
+	case 0:
+		return "success";
+	case -ENOENT:
+		return "unlinked (sync)";
+	case -EINPROGRESS:
+		return "URB still pending";
+	case -EPROTO:
+		return "bitstuff error, timeout, or unknown USB error";
+	case -EILSEQ:
+		return "CRC mismatch, timeout, or unknown USB error";
+	case -ETIME:
+		return "USB response timeout";
+	case -EPIPE:
+		return "endpoint stalled";
+	case -ECOMM:
+		return "IN buffer overrun";
+	case -ENOSR:
+		return "OUT buffer underrun";
+	case -EOVERFLOW:
+		return "endpoint babble";
+	case -EREMOTEIO:
+		return "short packet";
+	case -ENODEV:
+		return "device removed";
+	case -EXDEV:
+		return "partial isoc transfer";
+	case -EINVAL:
+		return "ISO madness";
+	case -ECONNRESET:
+		return "unlinked (async)";
+	case -ESHUTDOWN:
+		return "device shut down";
+	default:
+		snprintf(unkmsg, sizeof(unkmsg), "unknown status %d", status);
+		return unkmsg;
+	}
+}
+
+/* usb_pipetype_str
+ * retrieve string representation of USB pipe type
+ */
+static inline char *usb_pipetype_str(int pipe)
+{
+	if (usb_pipeisoc(pipe))
+		return "Isoc";
+	if (usb_pipeint(pipe))
+		return "Int";
+	if (usb_pipecontrol(pipe))
+		return "Ctrl";
+	if (usb_pipebulk(pipe))
+		return "Bulk";
+	return "?";
+}
+
+/* dump_urb
+ * write content of URB to syslog for debugging
+ */
+static inline void dump_urb(enum debuglevel level, const char *tag,
+			    struct urb *urb)
+{
+#ifdef CONFIG_GIGASET_DEBUG
+	int i;
+	gig_dbg(level, "%s urb(0x%08lx)->{", tag, (unsigned long) urb);
+	if (urb) {
+		gig_dbg(level,
+			"  dev=0x%08lx, pipe=%s:EP%d/DV%d:%s, "
+			"hcpriv=0x%08lx, transfer_flags=0x%x,",
+			(unsigned long) urb->dev,
+			usb_pipetype_str(urb->pipe),
+			usb_pipeendpoint(urb->pipe), usb_pipedevice(urb->pipe),
+			usb_pipein(urb->pipe) ? "in" : "out",
+			(unsigned long) urb->hcpriv,
+			urb->transfer_flags);
+		gig_dbg(level,
+			"  transfer_buffer=0x%08lx[%d], actual_length=%d, "
+			"setup_packet=0x%08lx,",
+			(unsigned long) urb->transfer_buffer,
+			urb->transfer_buffer_length, urb->actual_length,
+			(unsigned long) urb->setup_packet);
+		gig_dbg(level,
+			"  start_frame=%d, number_of_packets=%d, interval=%d, "
+			"error_count=%d,",
+			urb->start_frame, urb->number_of_packets, urb->interval,
+			urb->error_count);
+		gig_dbg(level,
+			"  context=0x%08lx, complete=0x%08lx, "
+			"iso_frame_desc[]={",
+			(unsigned long) urb->context,
+			(unsigned long) urb->complete);
+		for (i = 0; i < urb->number_of_packets; i++) {
+			struct usb_iso_packet_descriptor *pifd
+				= &urb->iso_frame_desc[i];
+			gig_dbg(level,
+				"    {offset=%u, length=%u, actual_length=%u, "
+				"status=%u}",
+				pifd->offset, pifd->length, pifd->actual_length,
+				pifd->status);
+		}
+	}
+	gig_dbg(level, "}}");
+#endif
+}
+
+/* read/set modem control bits etc. (m10x only) */
+static int gigaset_set_modem_ctrl(struct cardstate *cs, unsigned old_state,
+				  unsigned new_state)
+{
+	return -EINVAL;
+}
+
+static int gigaset_baud_rate(struct cardstate *cs, unsigned cflag)
+{
+	return -EINVAL;
+}
+
+static int gigaset_set_line_ctrl(struct cardstate *cs, unsigned cflag)
+{
+	return -EINVAL;
+}
+
+/* set/clear bits in base connection state, return previous state
+ */
+static inline int update_basstate(struct bas_cardstate *ucs,
+				  int set, int clear)
+{
+	unsigned long flags;
+	int state;
+
+	spin_lock_irqsave(&ucs->lock, flags);
+	state = ucs->basstate;
+	ucs->basstate = (state & ~clear) | set;
+	spin_unlock_irqrestore(&ucs->lock, flags);
+	return state;
+}
+
+/* error_hangup
+ * hang up any existing connection because of an unrecoverable error
+ * This function may be called from any context and takes care of scheduling
+ * the necessary actions for execution outside of interrupt context.
+ * cs->lock must not be held.
+ * argument:
+ *	B channel control structure
+ */
+static inline void error_hangup(struct bc_state *bcs)
+{
+	struct cardstate *cs = bcs->cs;
+
+	gigaset_add_event(cs, &bcs->at_state, EV_HUP, NULL, 0, NULL);
+	gigaset_schedule_event(cs);
+}
+
+/* error_reset
+ * reset Gigaset device because of an unrecoverable error
+ * This function may be called from any context, and takes care of
+ * scheduling the necessary actions for execution outside of interrupt context.
+ * cs->hw.bas->lock must not be held.
+ * argument:
+ *	controller state structure
+ */
+static inline void error_reset(struct cardstate *cs)
+{
+	/* reset interrupt pipe to recover (ignore errors) */
+	update_basstate(cs->hw.bas, BS_RESETTING, 0);
+	if (req_submit(cs->bcs, HD_RESET_INTERRUPT_PIPE, 0, BAS_TIMEOUT))
+		/* submission failed, escalate to USB port reset */
+		usb_queue_reset_device(cs->hw.bas->interface);
+}
+
+/* check_pending
+ * check for completion of pending control request
+ * parameter:
+ *	ucs	hardware specific controller state structure
+ */
+static void check_pending(struct bas_cardstate *ucs)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ucs->lock, flags);
+	switch (ucs->pending) {
+	case 0:
+		break;
+	case HD_OPEN_ATCHANNEL:
+		if (ucs->basstate & BS_ATOPEN)
+			ucs->pending = 0;
+		break;
+	case HD_OPEN_B1CHANNEL:
+		if (ucs->basstate & BS_B1OPEN)
+			ucs->pending = 0;
+		break;
+	case HD_OPEN_B2CHANNEL:
+		if (ucs->basstate & BS_B2OPEN)
+			ucs->pending = 0;
+		break;
+	case HD_CLOSE_ATCHANNEL:
+		if (!(ucs->basstate & BS_ATOPEN))
+			ucs->pending = 0;
+		break;
+	case HD_CLOSE_B1CHANNEL:
+		if (!(ucs->basstate & BS_B1OPEN))
+			ucs->pending = 0;
+		break;
+	case HD_CLOSE_B2CHANNEL:
+		if (!(ucs->basstate & BS_B2OPEN))
+			ucs->pending = 0;
+		break;
+	case HD_DEVICE_INIT_ACK:		/* no reply expected */
+		ucs->pending = 0;
+		break;
+	case HD_RESET_INTERRUPT_PIPE:
+		if (!(ucs->basstate & BS_RESETTING))
+			ucs->pending = 0;
+		break;
+	/*
+	 * HD_READ_ATMESSAGE and HD_WRITE_ATMESSAGE are handled separately
+	 * and should never end up here
+	 */
+	default:
+		dev_warn(&ucs->interface->dev,
+			 "unknown pending request 0x%02x cleared\n",
+			 ucs->pending);
+		ucs->pending = 0;
+	}
+
+	if (!ucs->pending)
+		del_timer(&ucs->timer_ctrl);
+
+	spin_unlock_irqrestore(&ucs->lock, flags);
+}
+
+/* cmd_in_timeout
+ * timeout routine for command input request
+ * argument:
+ *	controller state structure
+ */
+static void cmd_in_timeout(unsigned long data)
+{
+	struct cardstate *cs = (struct cardstate *) data;
+	struct bas_cardstate *ucs = cs->hw.bas;
+	int rc;
+
+	if (!ucs->rcvbuf_size) {
+		gig_dbg(DEBUG_USBREQ, "%s: no receive in progress", __func__);
+		return;
+	}
+
+	if (ucs->retry_cmd_in++ >= BAS_RETRY) {
+		dev_err(cs->dev,
+			"control read: timeout, giving up after %d tries\n",
+			ucs->retry_cmd_in);
+		kfree(ucs->rcvbuf);
+		ucs->rcvbuf = NULL;
+		ucs->rcvbuf_size = 0;
+		error_reset(cs);
+		return;
+	}
+
+	gig_dbg(DEBUG_USBREQ, "%s: timeout, retry %d",
+		__func__, ucs->retry_cmd_in);
+	rc = atread_submit(cs, BAS_TIMEOUT);
+	if (rc < 0) {
+		kfree(ucs->rcvbuf);
+		ucs->rcvbuf = NULL;
+		ucs->rcvbuf_size = 0;
+		if (rc != -ENODEV)
+			error_reset(cs);
+	}
+}
+
+/* read_ctrl_callback
+ * USB completion handler for control pipe input
+ * called by the USB subsystem in interrupt context
+ * parameter:
+ *	urb	USB request block
+ *		urb->context = inbuf structure for controller state
+ */
+static void read_ctrl_callback(struct urb *urb)
+{
+	struct inbuf_t *inbuf = urb->context;
+	struct cardstate *cs = inbuf->cs;
+	struct bas_cardstate *ucs = cs->hw.bas;
+	int status = urb->status;
+	unsigned numbytes;
+	int rc;
+
+	update_basstate(ucs, 0, BS_ATRDPEND);
+	wake_up(&ucs->waitqueue);
+	del_timer(&ucs->timer_cmd_in);
+
+	switch (status) {
+	case 0:				/* normal completion */
+		numbytes = urb->actual_length;
+		if (unlikely(numbytes != ucs->rcvbuf_size)) {
+			dev_warn(cs->dev,
+				 "control read: received %d chars, expected %d\n",
+				 numbytes, ucs->rcvbuf_size);
+			if (numbytes > ucs->rcvbuf_size)
+				numbytes = ucs->rcvbuf_size;
+		}
+
+		/* copy received bytes to inbuf, notify event layer */
+		if (gigaset_fill_inbuf(inbuf, ucs->rcvbuf, numbytes)) {
+			gig_dbg(DEBUG_INTR, "%s-->BH", __func__);
+			gigaset_schedule_event(cs);
+		}
+		break;
+
+	case -ENOENT:			/* cancelled */
+	case -ECONNRESET:		/* cancelled (async) */
+	case -EINPROGRESS:		/* pending */
+	case -ENODEV:			/* device removed */
+	case -ESHUTDOWN:		/* device shut down */
+		/* no further action necessary */
+		gig_dbg(DEBUG_USBREQ, "%s: %s",
+			__func__, get_usb_statmsg(status));
+		break;
+
+	default:			/* other errors: retry */
+		if (ucs->retry_cmd_in++ < BAS_RETRY) {
+			gig_dbg(DEBUG_USBREQ, "%s: %s, retry %d", __func__,
+				get_usb_statmsg(status), ucs->retry_cmd_in);
+			rc = atread_submit(cs, BAS_TIMEOUT);
+			if (rc >= 0)
+				/* successfully resubmitted, skip freeing */
+				return;
+			if (rc == -ENODEV)
+				/* disconnect, no further action necessary */
+				break;
+		}
+		dev_err(cs->dev, "control read: %s, giving up after %d tries\n",
+			get_usb_statmsg(status), ucs->retry_cmd_in);
+		error_reset(cs);
+	}
+
+	/* read finished, free buffer */
+	kfree(ucs->rcvbuf);
+	ucs->rcvbuf = NULL;
+	ucs->rcvbuf_size = 0;
+}
+
+/* atread_submit
+ * submit an HD_READ_ATMESSAGE command URB and optionally start a timeout
+ * parameters:
+ *	cs	controller state structure
+ *	timeout	timeout in 1/10 sec., 0: none
+ * return value:
+ *	0 on success
+ *	-EBUSY if another request is pending
+ *	any URB submission error code
+ */
+static int atread_submit(struct cardstate *cs, int timeout)
+{
+	struct bas_cardstate *ucs = cs->hw.bas;
+	int basstate;
+	int ret;
+
+	gig_dbg(DEBUG_USBREQ, "-------> HD_READ_ATMESSAGE (%d)",
+		ucs->rcvbuf_size);
+
+	basstate = update_basstate(ucs, BS_ATRDPEND, 0);
+	if (basstate & BS_ATRDPEND) {
+		dev_err(cs->dev,
+			"could not submit HD_READ_ATMESSAGE: URB busy\n");
+		return -EBUSY;
+	}
+
+	if (basstate & BS_SUSPEND) {
+		dev_notice(cs->dev,
+			   "HD_READ_ATMESSAGE not submitted, "
+			   "suspend in progress\n");
+		update_basstate(ucs, 0, BS_ATRDPEND);
+		/* treat like disconnect */
+		return -ENODEV;
+	}
+
+	ucs->dr_cmd_in.bRequestType = IN_VENDOR_REQ;
+	ucs->dr_cmd_in.bRequest = HD_READ_ATMESSAGE;
+	ucs->dr_cmd_in.wValue = 0;
+	ucs->dr_cmd_in.wIndex = 0;
+	ucs->dr_cmd_in.wLength = cpu_to_le16(ucs->rcvbuf_size);
+	usb_fill_control_urb(ucs->urb_cmd_in, ucs->udev,
+			     usb_rcvctrlpipe(ucs->udev, 0),
+			     (unsigned char *) &ucs->dr_cmd_in,
+			     ucs->rcvbuf, ucs->rcvbuf_size,
+			     read_ctrl_callback, cs->inbuf);
+
+	ret = usb_submit_urb(ucs->urb_cmd_in, GFP_ATOMIC);
+	if (ret != 0) {
+		update_basstate(ucs, 0, BS_ATRDPEND);
+		dev_err(cs->dev, "could not submit HD_READ_ATMESSAGE: %s\n",
+			get_usb_rcmsg(ret));
+		return ret;
+	}
+
+	if (timeout > 0) {
+		gig_dbg(DEBUG_USBREQ, "setting timeout of %d/10 secs", timeout);
+		mod_timer(&ucs->timer_cmd_in, jiffies + timeout * HZ / 10);
+	}
+	return 0;
+}
+
+/* int_in_work
+ * workqueue routine to clear halt on interrupt in endpoint
+ */
+
+static void int_in_work(struct work_struct *work)
+{
+	struct bas_cardstate *ucs =
+		container_of(work, struct bas_cardstate, int_in_wq);
+	struct urb *urb = ucs->urb_int_in;
+	struct cardstate *cs = urb->context;
+	int rc;
+
+	/* clear halt condition */
+	rc = usb_clear_halt(ucs->udev, urb->pipe);
+	gig_dbg(DEBUG_USBREQ, "clear_halt: %s", get_usb_rcmsg(rc));
+	if (rc == 0)
+		/* success, resubmit interrupt read URB */
+		rc = usb_submit_urb(urb, GFP_ATOMIC);
+
+	switch (rc) {
+	case 0:		/* success */
+	case -ENODEV:	/* device gone */
+	case -EINVAL:	/* URB already resubmitted, or terminal badness */
+		break;
+	default:	/* failure: try to recover by resetting the device */
+		dev_err(cs->dev, "clear halt failed: %s\n", get_usb_rcmsg(rc));
+		rc = usb_lock_device_for_reset(ucs->udev, ucs->interface);
+		if (rc == 0) {
+			rc = usb_reset_device(ucs->udev);
+			usb_unlock_device(ucs->udev);
+		}
+	}
+	ucs->retry_int_in = 0;
+}
+
+/* int_in_resubmit
+ * timer routine for interrupt read delayed resubmit
+ * argument:
+ *	controller state structure
+ */
+static void int_in_resubmit(unsigned long data)
+{
+	struct cardstate *cs = (struct cardstate *) data;
+	struct bas_cardstate *ucs = cs->hw.bas;
+	int rc;
+
+	if (ucs->retry_int_in++ >= BAS_RETRY) {
+		dev_err(cs->dev, "interrupt read: giving up after %d tries\n",
+			ucs->retry_int_in);
+		usb_queue_reset_device(ucs->interface);
+		return;
+	}
+
+	gig_dbg(DEBUG_USBREQ, "%s: retry %d", __func__, ucs->retry_int_in);
+	rc = usb_submit_urb(ucs->urb_int_in, GFP_ATOMIC);
+	if (rc != 0 && rc != -ENODEV) {
+		dev_err(cs->dev, "could not resubmit interrupt URB: %s\n",
+			get_usb_rcmsg(rc));
+		usb_queue_reset_device(ucs->interface);
+	}
+}
+
+/* read_int_callback
+ * USB completion handler for interrupt pipe input
+ * called by the USB subsystem in interrupt context
+ * parameter:
+ *	urb	USB request block
+ *		urb->context = controller state structure
+ */
+static void read_int_callback(struct urb *urb)
+{
+	struct cardstate *cs = urb->context;
+	struct bas_cardstate *ucs = cs->hw.bas;
+	struct bc_state *bcs;
+	int status = urb->status;
+	unsigned long flags;
+	int rc;
+	unsigned l;
+	int channel;
+
+	switch (status) {
+	case 0:			/* success */
+		ucs->retry_int_in = 0;
+		break;
+	case -EPIPE:			/* endpoint stalled */
+		schedule_work(&ucs->int_in_wq);
+		/* fall through */
+	case -ENOENT:			/* cancelled */
+	case -ECONNRESET:		/* cancelled (async) */
+	case -EINPROGRESS:		/* pending */
+	case -ENODEV:			/* device removed */
+	case -ESHUTDOWN:		/* device shut down */
+		/* no further action necessary */
+		gig_dbg(DEBUG_USBREQ, "%s: %s",
+			__func__, get_usb_statmsg(status));
+		return;
+	case -EPROTO:			/* protocol error or unplug */
+	case -EILSEQ:
+	case -ETIME:
+		/* resubmit after delay */
+		gig_dbg(DEBUG_USBREQ, "%s: %s",
+			__func__, get_usb_statmsg(status));
+		mod_timer(&ucs->timer_int_in, jiffies + HZ / 10);
+		return;
+	default:		/* other errors: just resubmit */
+		dev_warn(cs->dev, "interrupt read: %s\n",
+			 get_usb_statmsg(status));
+		goto resubmit;
+	}
+
+	/* drop incomplete packets even if the missing bytes wouldn't matter */
+	if (unlikely(urb->actual_length < IP_MSGSIZE)) {
+		dev_warn(cs->dev, "incomplete interrupt packet (%d bytes)\n",
+			 urb->actual_length);
+		goto resubmit;
+	}
+
+	l = (unsigned) ucs->int_in_buf[1] +
+		(((unsigned) ucs->int_in_buf[2]) << 8);
+
+	gig_dbg(DEBUG_USBREQ, "<-------%d: 0x%02x (%u [0x%02x 0x%02x])",
+		urb->actual_length, (int)ucs->int_in_buf[0], l,
+		(int)ucs->int_in_buf[1], (int)ucs->int_in_buf[2]);
+
+	channel = 0;
+
+	switch (ucs->int_in_buf[0]) {
+	case HD_DEVICE_INIT_OK:
+		update_basstate(ucs, BS_INIT, 0);
+		break;
+
+	case HD_READY_SEND_ATDATA:
+		del_timer(&ucs->timer_atrdy);
+		update_basstate(ucs, BS_ATREADY, BS_ATTIMER);
+		start_cbsend(cs);
+		break;
+
+	case HD_OPEN_B2CHANNEL_ACK:
+		++channel;
+	case HD_OPEN_B1CHANNEL_ACK:
+		bcs = cs->bcs + channel;
+		update_basstate(ucs, BS_B1OPEN << channel, 0);
+		gigaset_bchannel_up(bcs);
+		break;
+
+	case HD_OPEN_ATCHANNEL_ACK:
+		update_basstate(ucs, BS_ATOPEN, 0);
+		start_cbsend(cs);
+		break;
+
+	case HD_CLOSE_B2CHANNEL_ACK:
+		++channel;
+	case HD_CLOSE_B1CHANNEL_ACK:
+		bcs = cs->bcs + channel;
+		update_basstate(ucs, 0, BS_B1OPEN << channel);
+		stopurbs(bcs->hw.bas);
+		gigaset_bchannel_down(bcs);
+		break;
+
+	case HD_CLOSE_ATCHANNEL_ACK:
+		update_basstate(ucs, 0, BS_ATOPEN);
+		break;
+
+	case HD_B2_FLOW_CONTROL:
+		++channel;
+	case HD_B1_FLOW_CONTROL:
+		bcs = cs->bcs + channel;
+		atomic_add((l - BAS_NORMFRAME) * BAS_CORRFRAMES,
+			   &bcs->hw.bas->corrbytes);
+		gig_dbg(DEBUG_ISO,
+			"Flow control (channel %d, sub %d): 0x%02x => %d",
+			channel, bcs->hw.bas->numsub, l,
+			atomic_read(&bcs->hw.bas->corrbytes));
+		break;
+
+	case HD_RECEIVEATDATA_ACK:	/* AT response ready to be received */
+		if (!l) {
+			dev_warn(cs->dev,
+				 "HD_RECEIVEATDATA_ACK with length 0 ignored\n");
+			break;
+		}
+		spin_lock_irqsave(&cs->lock, flags);
+		if (ucs->basstate & BS_ATRDPEND) {
+			spin_unlock_irqrestore(&cs->lock, flags);
+			dev_warn(cs->dev,
+				 "HD_RECEIVEATDATA_ACK(%d) during HD_READ_ATMESSAGE(%d) ignored\n",
+				 l, ucs->rcvbuf_size);
+			break;
+		}
+		if (ucs->rcvbuf_size) {
+			/* throw away previous buffer - we have no queue */
+			dev_err(cs->dev,
+				"receive AT data overrun, %d bytes lost\n",
+				ucs->rcvbuf_size);
+			kfree(ucs->rcvbuf);
+			ucs->rcvbuf_size = 0;
+		}
+		ucs->rcvbuf = kmalloc(l, GFP_ATOMIC);
+		if (ucs->rcvbuf == NULL) {
+			spin_unlock_irqrestore(&cs->lock, flags);
+			dev_err(cs->dev, "out of memory receiving AT data\n");
+			break;
+		}
+		ucs->rcvbuf_size = l;
+		ucs->retry_cmd_in = 0;
+		rc = atread_submit(cs, BAS_TIMEOUT);
+		if (rc < 0) {
+			kfree(ucs->rcvbuf);
+			ucs->rcvbuf = NULL;
+			ucs->rcvbuf_size = 0;
+		}
+		spin_unlock_irqrestore(&cs->lock, flags);
+		if (rc < 0 && rc != -ENODEV)
+			error_reset(cs);
+		break;
+
+	case HD_RESET_INTERRUPT_PIPE_ACK:
+		update_basstate(ucs, 0, BS_RESETTING);
+		dev_notice(cs->dev, "interrupt pipe reset\n");
+		break;
+
+	case HD_SUSPEND_END:
+		gig_dbg(DEBUG_USBREQ, "HD_SUSPEND_END");
+		break;
+
+	default:
+		dev_warn(cs->dev,
+			 "unknown Gigaset signal 0x%02x (%u) ignored\n",
+			 (int) ucs->int_in_buf[0], l);
+	}
+
+	check_pending(ucs);
+	wake_up(&ucs->waitqueue);
+
+resubmit:
+	rc = usb_submit_urb(urb, GFP_ATOMIC);
+	if (unlikely(rc != 0 && rc != -ENODEV)) {
+		dev_err(cs->dev, "could not resubmit interrupt URB: %s\n",
+			get_usb_rcmsg(rc));
+		error_reset(cs);
+	}
+}
+
+/* read_iso_callback
+ * USB completion handler for B channel isochronous input
+ * called by the USB subsystem in interrupt context
+ * parameter:
+ *	urb	USB request block of completed request
+ *		urb->context = bc_state structure
+ */
+static void read_iso_callback(struct urb *urb)
+{
+	struct bc_state *bcs;
+	struct bas_bc_state *ubc;
+	int status = urb->status;
+	unsigned long flags;
+	int i, rc;
+
+	/* status codes not worth bothering the tasklet with */
+	if (unlikely(status == -ENOENT ||
+		     status == -ECONNRESET ||
+		     status == -EINPROGRESS ||
+		     status == -ENODEV ||
+		     status == -ESHUTDOWN)) {
+		gig_dbg(DEBUG_ISO, "%s: %s",
+			__func__, get_usb_statmsg(status));
+		return;
+	}
+
+	bcs = urb->context;
+	ubc = bcs->hw.bas;
+
+	spin_lock_irqsave(&ubc->isoinlock, flags);
+	if (likely(ubc->isoindone == NULL)) {
+		/* pass URB to tasklet */
+		ubc->isoindone = urb;
+		ubc->isoinstatus = status;
+		tasklet_hi_schedule(&ubc->rcvd_tasklet);
+	} else {
+		/* tasklet still busy, drop data and resubmit URB */
+		gig_dbg(DEBUG_ISO, "%s: overrun", __func__);
+		ubc->loststatus = status;
+		for (i = 0; i < BAS_NUMFRAMES; i++) {
+			ubc->isoinlost += urb->iso_frame_desc[i].actual_length;
+			if (unlikely(urb->iso_frame_desc[i].status != 0 &&
+				     urb->iso_frame_desc[i].status != -EINPROGRESS))
+				ubc->loststatus = urb->iso_frame_desc[i].status;
+			urb->iso_frame_desc[i].status = 0;
+			urb->iso_frame_desc[i].actual_length = 0;
+		}
+		if (likely(ubc->running)) {
+			/* urb->dev is clobbered by USB subsystem */
+			urb->dev = bcs->cs->hw.bas->udev;
+			urb->transfer_flags = URB_ISO_ASAP;
+			urb->number_of_packets = BAS_NUMFRAMES;
+			rc = usb_submit_urb(urb, GFP_ATOMIC);
+			if (unlikely(rc != 0 && rc != -ENODEV)) {
+				dev_err(bcs->cs->dev,
+					"could not resubmit isoc read URB: %s\n",
+					get_usb_rcmsg(rc));
+				dump_urb(DEBUG_ISO, "isoc read", urb);
+				error_hangup(bcs);
+			}
+		}
+	}
+	spin_unlock_irqrestore(&ubc->isoinlock, flags);
+}
+
+/* write_iso_callback
+ * USB completion handler for B channel isochronous output
+ * called by the USB subsystem in interrupt context
+ * parameter:
+ *	urb	USB request block of completed request
+ *		urb->context = isow_urbctx_t structure
+ */
+static void write_iso_callback(struct urb *urb)
+{
+	struct isow_urbctx_t *ucx;
+	struct bas_bc_state *ubc;
+	int status = urb->status;
+	unsigned long flags;
+
+	/* status codes not worth bothering the tasklet with */
+	if (unlikely(status == -ENOENT ||
+		     status == -ECONNRESET ||
+		     status == -EINPROGRESS ||
+		     status == -ENODEV ||
+		     status == -ESHUTDOWN)) {
+		gig_dbg(DEBUG_ISO, "%s: %s",
+			__func__, get_usb_statmsg(status));
+		return;
+	}
+
+	/* pass URB context to tasklet */
+	ucx = urb->context;
+	ubc = ucx->bcs->hw.bas;
+	ucx->status = status;
+
+	spin_lock_irqsave(&ubc->isooutlock, flags);
+	ubc->isooutovfl = ubc->isooutdone;
+	ubc->isooutdone = ucx;
+	spin_unlock_irqrestore(&ubc->isooutlock, flags);
+	tasklet_hi_schedule(&ubc->sent_tasklet);
+}
+
+/* starturbs
+ * prepare and submit USB request blocks for isochronous input and output
+ * argument:
+ *	B channel control structure
+ * return value:
+ *	0 on success
+ *	< 0 on error (no URBs submitted)
+ */
+static int starturbs(struct bc_state *bcs)
+{
+	struct bas_bc_state *ubc = bcs->hw.bas;
+	struct urb *urb;
+	int j, k;
+	int rc;
+
+	/* initialize L2 reception */
+	if (bcs->proto2 == L2_HDLC)
+		bcs->inputstate |= INS_flag_hunt;
+
+	/* submit all isochronous input URBs */
+	ubc->running = 1;
+	for (k = 0; k < BAS_INURBS; k++) {
+		urb = ubc->isoinurbs[k];
+		if (!urb) {
+			rc = -EFAULT;
+			goto error;
+		}
+
+		urb->dev = bcs->cs->hw.bas->udev;
+		urb->pipe = usb_rcvisocpipe(urb->dev, 3 + 2 * bcs->channel);
+		urb->transfer_flags = URB_ISO_ASAP;
+		urb->transfer_buffer = ubc->isoinbuf + k * BAS_INBUFSIZE;
+		urb->transfer_buffer_length = BAS_INBUFSIZE;
+		urb->number_of_packets = BAS_NUMFRAMES;
+		urb->interval = BAS_FRAMETIME;
+		urb->complete = read_iso_callback;
+		urb->context = bcs;
+		for (j = 0; j < BAS_NUMFRAMES; j++) {
+			urb->iso_frame_desc[j].offset = j * BAS_MAXFRAME;
+			urb->iso_frame_desc[j].length = BAS_MAXFRAME;
+			urb->iso_frame_desc[j].status = 0;
+			urb->iso_frame_desc[j].actual_length = 0;
+		}
+
+		dump_urb(DEBUG_ISO, "Initial isoc read", urb);
+		rc = usb_submit_urb(urb, GFP_ATOMIC);
+		if (rc != 0)
+			goto error;
+	}
+
+	/* initialize L2 transmission */
+	gigaset_isowbuf_init(ubc->isooutbuf, PPP_FLAG);
+
+	/* set up isochronous output URBs for flag idling */
+	for (k = 0; k < BAS_OUTURBS; ++k) {
+		urb = ubc->isoouturbs[k].urb;
+		if (!urb) {
+			rc = -EFAULT;
+			goto error;
+		}
+		urb->dev = bcs->cs->hw.bas->udev;
+		urb->pipe = usb_sndisocpipe(urb->dev, 4 + 2 * bcs->channel);
+		urb->transfer_flags = URB_ISO_ASAP;
+		urb->transfer_buffer = ubc->isooutbuf->data;
+		urb->transfer_buffer_length = sizeof(ubc->isooutbuf->data);
+		urb->number_of_packets = BAS_NUMFRAMES;
+		urb->interval = BAS_FRAMETIME;
+		urb->complete = write_iso_callback;
+		urb->context = &ubc->isoouturbs[k];
+		for (j = 0; j < BAS_NUMFRAMES; ++j) {
+			urb->iso_frame_desc[j].offset = BAS_OUTBUFSIZE;
+			urb->iso_frame_desc[j].length = BAS_NORMFRAME;
+			urb->iso_frame_desc[j].status = 0;
+			urb->iso_frame_desc[j].actual_length = 0;
+		}
+		ubc->isoouturbs[k].limit = -1;
+	}
+
+	/* keep one URB free, submit the others */
+	for (k = 0; k < BAS_OUTURBS - 1; ++k) {
+		dump_urb(DEBUG_ISO, "Initial isoc write", urb);
+		rc = usb_submit_urb(ubc->isoouturbs[k].urb, GFP_ATOMIC);
+		if (rc != 0)
+			goto error;
+	}
+	dump_urb(DEBUG_ISO, "Initial isoc write (free)", urb);
+	ubc->isooutfree = &ubc->isoouturbs[BAS_OUTURBS - 1];
+	ubc->isooutdone = ubc->isooutovfl = NULL;
+	return 0;
+error:
+	stopurbs(ubc);
+	return rc;
+}
+
+/* stopurbs
+ * cancel the USB request blocks for isochronous input and output
+ * errors are silently ignored
+ * argument:
+ *	B channel control structure
+ */
+static void stopurbs(struct bas_bc_state *ubc)
+{
+	int k, rc;
+
+	ubc->running = 0;
+
+	for (k = 0; k < BAS_INURBS; ++k) {
+		rc = usb_unlink_urb(ubc->isoinurbs[k]);
+		gig_dbg(DEBUG_ISO,
+			"%s: isoc input URB %d unlinked, result = %s",
+			__func__, k, get_usb_rcmsg(rc));
+	}
+
+	for (k = 0; k < BAS_OUTURBS; ++k) {
+		rc = usb_unlink_urb(ubc->isoouturbs[k].urb);
+		gig_dbg(DEBUG_ISO,
+			"%s: isoc output URB %d unlinked, result = %s",
+			__func__, k, get_usb_rcmsg(rc));
+	}
+}
+
+/* Isochronous Write - Bottom Half */
+/* =============================== */
+
+/* submit_iso_write_urb
+ * fill and submit the next isochronous write URB
+ * parameters:
+ *	ucx	context structure containing URB
+ * return value:
+ *	number of frames submitted in URB
+ *	0 if URB not submitted because no data available (isooutbuf busy)
+ *	error code < 0 on error
+ */
+static int submit_iso_write_urb(struct isow_urbctx_t *ucx)
+{
+	struct urb *urb = ucx->urb;
+	struct bas_bc_state *ubc = ucx->bcs->hw.bas;
+	struct usb_iso_packet_descriptor *ifd;
+	int corrbytes, nframe, rc;
+
+	/* urb->dev is clobbered by USB subsystem */
+	urb->dev = ucx->bcs->cs->hw.bas->udev;
+	urb->transfer_flags = URB_ISO_ASAP;
+	urb->transfer_buffer = ubc->isooutbuf->data;
+	urb->transfer_buffer_length = sizeof(ubc->isooutbuf->data);
+
+	for (nframe = 0; nframe < BAS_NUMFRAMES; nframe++) {
+		ifd = &urb->iso_frame_desc[nframe];
+
+		/* compute frame length according to flow control */
+		ifd->length = BAS_NORMFRAME;
+		corrbytes = atomic_read(&ubc->corrbytes);
+		if (corrbytes != 0) {
+			gig_dbg(DEBUG_ISO, "%s: corrbytes=%d",
+				__func__, corrbytes);
+			if (corrbytes > BAS_HIGHFRAME - BAS_NORMFRAME)
+				corrbytes = BAS_HIGHFRAME - BAS_NORMFRAME;
+			else if (corrbytes < BAS_LOWFRAME - BAS_NORMFRAME)
+				corrbytes = BAS_LOWFRAME - BAS_NORMFRAME;
+			ifd->length += corrbytes;
+			atomic_add(-corrbytes, &ubc->corrbytes);
+		}
+
+		/* retrieve block of data to send */
+		rc = gigaset_isowbuf_getbytes(ubc->isooutbuf, ifd->length);
+		if (rc < 0) {
+			if (rc == -EBUSY) {
+				gig_dbg(DEBUG_ISO,
+					"%s: buffer busy at frame %d",
+					__func__, nframe);
+				/* tasklet will be restarted from
+				   gigaset_isoc_send_skb() */
+			} else {
+				dev_err(ucx->bcs->cs->dev,
+					"%s: buffer error %d at frame %d\n",
+					__func__, rc, nframe);
+				return rc;
+			}
+			break;
+		}
+		ifd->offset = rc;
+		ucx->limit = ubc->isooutbuf->nextread;
+		ifd->status = 0;
+		ifd->actual_length = 0;
+	}
+	if (unlikely(nframe == 0))
+		return 0;	/* no data to send */
+	urb->number_of_packets = nframe;
+
+	rc = usb_submit_urb(urb, GFP_ATOMIC);
+	if (unlikely(rc)) {
+		if (rc == -ENODEV)
+			/* device removed - give up silently */
+			gig_dbg(DEBUG_ISO, "%s: disconnected", __func__);
+		else
+			dev_err(ucx->bcs->cs->dev,
+				"could not submit isoc write URB: %s\n",
+				get_usb_rcmsg(rc));
+		return rc;
+	}
+	++ubc->numsub;
+	return nframe;
+}
+
+/* write_iso_tasklet
+ * tasklet scheduled when an isochronous output URB from the Gigaset device
+ * has completed
+ * parameter:
+ *	data	B channel state structure
+ */
+static void write_iso_tasklet(unsigned long data)
+{
+	struct bc_state *bcs = (struct bc_state *) data;
+	struct bas_bc_state *ubc = bcs->hw.bas;
+	struct cardstate *cs = bcs->cs;
+	struct isow_urbctx_t *done, *next, *ovfl;
+	struct urb *urb;
+	int status;
+	struct usb_iso_packet_descriptor *ifd;
+	unsigned long flags;
+	int i;
+	struct sk_buff *skb;
+	int len;
+	int rc;
+
+	/* loop while completed URBs arrive in time */
+	for (;;) {
+		if (unlikely(!(ubc->running))) {
+			gig_dbg(DEBUG_ISO, "%s: not running", __func__);
+			return;
+		}
+
+		/* retrieve completed URBs */
+		spin_lock_irqsave(&ubc->isooutlock, flags);
+		done = ubc->isooutdone;
+		ubc->isooutdone = NULL;
+		ovfl = ubc->isooutovfl;
+		ubc->isooutovfl = NULL;
+		spin_unlock_irqrestore(&ubc->isooutlock, flags);
+		if (ovfl) {
+			dev_err(cs->dev, "isoc write underrun\n");
+			error_hangup(bcs);
+			break;
+		}
+		if (!done)
+			break;
+
+		/* submit free URB if available */
+		spin_lock_irqsave(&ubc->isooutlock, flags);
+		next = ubc->isooutfree;
+		ubc->isooutfree = NULL;
+		spin_unlock_irqrestore(&ubc->isooutlock, flags);
+		if (next) {
+			rc = submit_iso_write_urb(next);
+			if (unlikely(rc <= 0 && rc != -ENODEV)) {
+				/* could not submit URB, put it back */
+				spin_lock_irqsave(&ubc->isooutlock, flags);
+				if (ubc->isooutfree == NULL) {
+					ubc->isooutfree = next;
+					next = NULL;
+				}
+				spin_unlock_irqrestore(&ubc->isooutlock, flags);
+				if (next) {
+					/* couldn't put it back */
+					dev_err(cs->dev,
+						"losing isoc write URB\n");
+					error_hangup(bcs);
+				}
+			}
+		}
+
+		/* process completed URB */
+		urb = done->urb;
+		status = done->status;
+		switch (status) {
+		case -EXDEV:			/* partial completion */
+			gig_dbg(DEBUG_ISO, "%s: URB partially completed",
+				__func__);
+			/* fall through - what's the difference anyway? */
+		case 0:				/* normal completion */
+			/* inspect individual frames
+			 * assumptions (for lack of documentation):
+			 * - actual_length bytes of first frame in error are
+			 *   successfully sent
+			 * - all following frames are not sent at all
+			 */
+			for (i = 0; i < BAS_NUMFRAMES; i++) {
+				ifd = &urb->iso_frame_desc[i];
+				if (ifd->status ||
+				    ifd->actual_length != ifd->length) {
+					dev_warn(cs->dev,
+						 "isoc write: frame %d[%d/%d]: %s\n",
+						 i, ifd->actual_length,
+						 ifd->length,
+						 get_usb_statmsg(ifd->status));
+					break;
+				}
+			}
+			break;
+		case -EPIPE:			/* stall - probably underrun */
+			dev_err(cs->dev, "isoc write: stalled\n");
+			error_hangup(bcs);
+			break;
+		default:			/* other errors */
+			dev_warn(cs->dev, "isoc write: %s\n",
+				 get_usb_statmsg(status));
+		}
+
+		/* mark the write buffer area covered by this URB as free */
+		if (done->limit >= 0)
+			ubc->isooutbuf->read = done->limit;
+
+		/* mark URB as free */
+		spin_lock_irqsave(&ubc->isooutlock, flags);
+		next = ubc->isooutfree;
+		ubc->isooutfree = done;
+		spin_unlock_irqrestore(&ubc->isooutlock, flags);
+		if (next) {
+			/* only one URB still active - resubmit one */
+			rc = submit_iso_write_urb(next);
+			if (unlikely(rc <= 0 && rc != -ENODEV)) {
+				/* couldn't submit */
+				error_hangup(bcs);
+			}
+		}
+	}
+
+	/* process queued SKBs */
+	while ((skb = skb_dequeue(&bcs->squeue))) {
+		/* copy to output buffer, doing L2 encapsulation */
+		len = skb->len;
+		if (gigaset_isoc_buildframe(bcs, skb->data, len) == -EAGAIN) {
+			/* insufficient buffer space, push back onto queue */
+			skb_queue_head(&bcs->squeue, skb);
+			gig_dbg(DEBUG_ISO, "%s: skb requeued, qlen=%d",
+				__func__, skb_queue_len(&bcs->squeue));
+			break;
+		}
+		skb_pull(skb, len);
+		gigaset_skb_sent(bcs, skb);
+		dev_kfree_skb_any(skb);
+	}
+}
+
+/* Isochronous Read - Bottom Half */
+/* ============================== */
+
+/* read_iso_tasklet
+ * tasklet scheduled when an isochronous input URB from the Gigaset device
+ * has completed
+ * parameter:
+ *	data	B channel state structure
+ */
+static void read_iso_tasklet(unsigned long data)
+{
+	struct bc_state *bcs = (struct bc_state *) data;
+	struct bas_bc_state *ubc = bcs->hw.bas;
+	struct cardstate *cs = bcs->cs;
+	struct urb *urb;
+	int status;
+	struct usb_iso_packet_descriptor *ifd;
+	char *rcvbuf;
+	unsigned long flags;
+	int totleft, numbytes, offset, frame, rc;
+
+	/* loop while more completed URBs arrive in the meantime */
+	for (;;) {
+		/* retrieve URB */
+		spin_lock_irqsave(&ubc->isoinlock, flags);
+		urb = ubc->isoindone;
+		if (!urb) {
+			spin_unlock_irqrestore(&ubc->isoinlock, flags);
+			return;
+		}
+		status = ubc->isoinstatus;
+		ubc->isoindone = NULL;
+		if (unlikely(ubc->loststatus != -EINPROGRESS)) {
+			dev_warn(cs->dev,
+				 "isoc read overrun, URB dropped (status: %s, %d bytes)\n",
+				 get_usb_statmsg(ubc->loststatus),
+				 ubc->isoinlost);
+			ubc->loststatus = -EINPROGRESS;
+		}
+		spin_unlock_irqrestore(&ubc->isoinlock, flags);
+
+		if (unlikely(!(ubc->running))) {
+			gig_dbg(DEBUG_ISO,
+				"%s: channel not running, "
+				"dropped URB with status: %s",
+				__func__, get_usb_statmsg(status));
+			return;
+		}
+
+		switch (status) {
+		case 0:				/* normal completion */
+			break;
+		case -EXDEV:			/* inspect individual frames
+						   (we do that anyway) */
+			gig_dbg(DEBUG_ISO, "%s: URB partially completed",
+				__func__);
+			break;
+		case -ENOENT:
+		case -ECONNRESET:
+		case -EINPROGRESS:
+			gig_dbg(DEBUG_ISO, "%s: %s",
+				__func__, get_usb_statmsg(status));
+			continue;		/* -> skip */
+		case -EPIPE:
+			dev_err(cs->dev, "isoc read: stalled\n");
+			error_hangup(bcs);
+			continue;		/* -> skip */
+		default:			/* other error */
+			dev_warn(cs->dev, "isoc read: %s\n",
+				 get_usb_statmsg(status));
+			goto error;
+		}
+
+		rcvbuf = urb->transfer_buffer;
+		totleft = urb->actual_length;
+		for (frame = 0; totleft > 0 && frame < BAS_NUMFRAMES; frame++) {
+			ifd = &urb->iso_frame_desc[frame];
+			numbytes = ifd->actual_length;
+			switch (ifd->status) {
+			case 0:			/* success */
+				break;
+			case -EPROTO:		/* protocol error or unplug */
+			case -EILSEQ:
+			case -ETIME:
+				/* probably just disconnected, ignore */
+				gig_dbg(DEBUG_ISO,
+					"isoc read: frame %d[%d]: %s\n",
+					frame, numbytes,
+					get_usb_statmsg(ifd->status));
+				break;
+			default:		/* other error */
+				/* report, assume transferred bytes are ok */
+				dev_warn(cs->dev,
+					 "isoc read: frame %d[%d]: %s\n",
+					 frame, numbytes,
+					 get_usb_statmsg(ifd->status));
+			}
+			if (unlikely(numbytes > BAS_MAXFRAME))
+				dev_warn(cs->dev,
+					 "isoc read: frame %d[%d]: %s\n",
+					 frame, numbytes,
+					 "exceeds max frame size");
+			if (unlikely(numbytes > totleft)) {
+				dev_warn(cs->dev,
+					 "isoc read: frame %d[%d]: %s\n",
+					 frame, numbytes,
+					 "exceeds total transfer length");
+				numbytes = totleft;
+			}
+			offset = ifd->offset;
+			if (unlikely(offset + numbytes > BAS_INBUFSIZE)) {
+				dev_warn(cs->dev,
+					 "isoc read: frame %d[%d]: %s\n",
+					 frame, numbytes,
+					 "exceeds end of buffer");
+				numbytes = BAS_INBUFSIZE - offset;
+			}
+			gigaset_isoc_receive(rcvbuf + offset, numbytes, bcs);
+			totleft -= numbytes;
+		}
+		if (unlikely(totleft > 0))
+			dev_warn(cs->dev, "isoc read: %d data bytes missing\n",
+				 totleft);
+
+error:
+		/* URB processed, resubmit */
+		for (frame = 0; frame < BAS_NUMFRAMES; frame++) {
+			urb->iso_frame_desc[frame].status = 0;
+			urb->iso_frame_desc[frame].actual_length = 0;
+		}
+		/* urb->dev is clobbered by USB subsystem */
+		urb->dev = bcs->cs->hw.bas->udev;
+		urb->transfer_flags = URB_ISO_ASAP;
+		urb->number_of_packets = BAS_NUMFRAMES;
+		rc = usb_submit_urb(urb, GFP_ATOMIC);
+		if (unlikely(rc != 0 && rc != -ENODEV)) {
+			dev_err(cs->dev,
+				"could not resubmit isoc read URB: %s\n",
+				get_usb_rcmsg(rc));
+			dump_urb(DEBUG_ISO, "resubmit isoc read", urb);
+			error_hangup(bcs);
+		}
+	}
+}
+
+/* Channel Operations */
+/* ================== */
+
+/* req_timeout
+ * timeout routine for control output request
+ * argument:
+ *	controller state structure
+ */
+static void req_timeout(unsigned long data)
+{
+	struct cardstate *cs = (struct cardstate *) data;
+	struct bas_cardstate *ucs = cs->hw.bas;
+	int pending;
+	unsigned long flags;
+
+	check_pending(ucs);
+
+	spin_lock_irqsave(&ucs->lock, flags);
+	pending = ucs->pending;
+	ucs->pending = 0;
+	spin_unlock_irqrestore(&ucs->lock, flags);
+
+	switch (pending) {
+	case 0:					/* no pending request */
+		gig_dbg(DEBUG_USBREQ, "%s: no request pending", __func__);
+		break;
+
+	case HD_OPEN_ATCHANNEL:
+		dev_err(cs->dev, "timeout opening AT channel\n");
+		error_reset(cs);
+		break;
+
+	case HD_OPEN_B1CHANNEL:
+		dev_err(cs->dev, "timeout opening channel 1\n");
+		error_hangup(&cs->bcs[0]);
+		break;
+
+	case HD_OPEN_B2CHANNEL:
+		dev_err(cs->dev, "timeout opening channel 2\n");
+		error_hangup(&cs->bcs[1]);
+		break;
+
+	case HD_CLOSE_ATCHANNEL:
+		dev_err(cs->dev, "timeout closing AT channel\n");
+		error_reset(cs);
+		break;
+
+	case HD_CLOSE_B1CHANNEL:
+		dev_err(cs->dev, "timeout closing channel 1\n");
+		error_reset(cs);
+		break;
+
+	case HD_CLOSE_B2CHANNEL:
+		dev_err(cs->dev, "timeout closing channel 2\n");
+		error_reset(cs);
+		break;
+
+	case HD_RESET_INTERRUPT_PIPE:
+		/* error recovery escalation */
+		dev_err(cs->dev,
+			"reset interrupt pipe timeout, attempting USB reset\n");
+		usb_queue_reset_device(ucs->interface);
+		break;
+
+	default:
+		dev_warn(cs->dev, "request 0x%02x timed out, clearing\n",
+			 pending);
+	}
+
+	wake_up(&ucs->waitqueue);
+}
+
+/* write_ctrl_callback
+ * USB completion handler for control pipe output
+ * called by the USB subsystem in interrupt context
+ * parameter:
+ *	urb	USB request block of completed request
+ *		urb->context = hardware specific controller state structure
+ */
+static void write_ctrl_callback(struct urb *urb)
+{
+	struct bas_cardstate *ucs = urb->context;
+	int status = urb->status;
+	int rc;
+	unsigned long flags;
+
+	/* check status */
+	switch (status) {
+	case 0:					/* normal completion */
+		spin_lock_irqsave(&ucs->lock, flags);
+		switch (ucs->pending) {
+		case HD_DEVICE_INIT_ACK:	/* no reply expected */
+			del_timer(&ucs->timer_ctrl);
+			ucs->pending = 0;
+			break;
+		}
+		spin_unlock_irqrestore(&ucs->lock, flags);
+		return;
+
+	case -ENOENT:			/* cancelled */
+	case -ECONNRESET:		/* cancelled (async) */
+	case -EINPROGRESS:		/* pending */
+	case -ENODEV:			/* device removed */
+	case -ESHUTDOWN:		/* device shut down */
+		/* ignore silently */
+		gig_dbg(DEBUG_USBREQ, "%s: %s",
+			__func__, get_usb_statmsg(status));
+		break;
+
+	default:				/* any failure */
+		/* don't retry if suspend requested */
+		if (++ucs->retry_ctrl > BAS_RETRY ||
+		    (ucs->basstate & BS_SUSPEND)) {
+			dev_err(&ucs->interface->dev,
+				"control request 0x%02x failed: %s\n",
+				ucs->dr_ctrl.bRequest,
+				get_usb_statmsg(status));
+			break;		/* give up */
+		}
+		dev_notice(&ucs->interface->dev,
+			   "control request 0x%02x: %s, retry %d\n",
+			   ucs->dr_ctrl.bRequest, get_usb_statmsg(status),
+			   ucs->retry_ctrl);
+		/* urb->dev is clobbered by USB subsystem */
+		urb->dev = ucs->udev;
+		rc = usb_submit_urb(urb, GFP_ATOMIC);
+		if (unlikely(rc)) {
+			dev_err(&ucs->interface->dev,
+				"could not resubmit request 0x%02x: %s\n",
+				ucs->dr_ctrl.bRequest, get_usb_rcmsg(rc));
+			break;
+		}
+		/* resubmitted */
+		return;
+	}
+
+	/* failed, clear pending request */
+	spin_lock_irqsave(&ucs->lock, flags);
+	del_timer(&ucs->timer_ctrl);
+	ucs->pending = 0;
+	spin_unlock_irqrestore(&ucs->lock, flags);
+	wake_up(&ucs->waitqueue);
+}
+
+/* req_submit
+ * submit a control output request without message buffer to the Gigaset base
+ * and optionally start a timeout
+ * parameters:
+ *	bcs	B channel control structure
+ *	req	control request code (HD_*)
+ *	val	control request parameter value (set to 0 if unused)
+ *	timeout	timeout in seconds (0: no timeout)
+ * return value:
+ *	0 on success
+ *	-EBUSY if another request is pending
+ *	any URB submission error code
+ */
+static int req_submit(struct bc_state *bcs, int req, int val, int timeout)
+{
+	struct bas_cardstate *ucs = bcs->cs->hw.bas;
+	int ret;
+	unsigned long flags;
+
+	gig_dbg(DEBUG_USBREQ, "-------> 0x%02x (%d)", req, val);
+
+	spin_lock_irqsave(&ucs->lock, flags);
+	if (ucs->pending) {
+		spin_unlock_irqrestore(&ucs->lock, flags);
+		dev_err(bcs->cs->dev,
+			"submission of request 0x%02x failed: "
+			"request 0x%02x still pending\n",
+			req, ucs->pending);
+		return -EBUSY;
+	}
+
+	ucs->dr_ctrl.bRequestType = OUT_VENDOR_REQ;
+	ucs->dr_ctrl.bRequest = req;
+	ucs->dr_ctrl.wValue = cpu_to_le16(val);
+	ucs->dr_ctrl.wIndex = 0;
+	ucs->dr_ctrl.wLength = 0;
+	usb_fill_control_urb(ucs->urb_ctrl, ucs->udev,
+			     usb_sndctrlpipe(ucs->udev, 0),
+			     (unsigned char *) &ucs->dr_ctrl, NULL, 0,
+			     write_ctrl_callback, ucs);
+	ucs->retry_ctrl = 0;
+	ret = usb_submit_urb(ucs->urb_ctrl, GFP_ATOMIC);
+	if (unlikely(ret)) {
+		dev_err(bcs->cs->dev, "could not submit request 0x%02x: %s\n",
+			req, get_usb_rcmsg(ret));
+		spin_unlock_irqrestore(&ucs->lock, flags);
+		return ret;
+	}
+	ucs->pending = req;
+
+	if (timeout > 0) {
+		gig_dbg(DEBUG_USBREQ, "setting timeout of %d/10 secs", timeout);
+		mod_timer(&ucs->timer_ctrl, jiffies + timeout * HZ / 10);
+	}
+
+	spin_unlock_irqrestore(&ucs->lock, flags);
+	return 0;
+}
+
+/* gigaset_init_bchannel
+ * called by common.c to connect a B channel
+ * initialize isochronous I/O and tell the Gigaset base to open the channel
+ * argument:
+ *	B channel control structure
+ * return value:
+ *	0 on success, error code < 0 on error
+ */
+static int gigaset_init_bchannel(struct bc_state *bcs)
+{
+	struct cardstate *cs = bcs->cs;
+	int req, ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cs->lock, flags);
+	if (unlikely(!cs->connected)) {
+		gig_dbg(DEBUG_USBREQ, "%s: not connected", __func__);
+		spin_unlock_irqrestore(&cs->lock, flags);
+		return -ENODEV;
+	}
+
+	if (cs->hw.bas->basstate & BS_SUSPEND) {
+		dev_notice(cs->dev,
+			   "not starting isoc I/O, suspend in progress\n");
+		spin_unlock_irqrestore(&cs->lock, flags);
+		return -EHOSTUNREACH;
+	}
+
+	ret = starturbs(bcs);
+	if (ret < 0) {
+		spin_unlock_irqrestore(&cs->lock, flags);
+		dev_err(cs->dev,
+			"could not start isoc I/O for channel B%d: %s\n",
+			bcs->channel + 1,
+			ret == -EFAULT ? "null URB" : get_usb_rcmsg(ret));
+		if (ret != -ENODEV)
+			error_hangup(bcs);
+		return ret;
+	}
+
+	req = bcs->channel ? HD_OPEN_B2CHANNEL : HD_OPEN_B1CHANNEL;
+	ret = req_submit(bcs, req, 0, BAS_TIMEOUT);
+	if (ret < 0) {
+		dev_err(cs->dev, "could not open channel B%d\n",
+			bcs->channel + 1);
+		stopurbs(bcs->hw.bas);
+	}
+
+	spin_unlock_irqrestore(&cs->lock, flags);
+	if (ret < 0 && ret != -ENODEV)
+		error_hangup(bcs);
+	return ret;
+}
+
+/* gigaset_close_bchannel
+ * called by common.c to disconnect a B channel
+ * tell the Gigaset base to close the channel
+ * stopping isochronous I/O and LL notification will be done when the
+ * acknowledgement for the close arrives
+ * argument:
+ *	B channel control structure
+ * return value:
+ *	0 on success, error code < 0 on error
+ */
+static int gigaset_close_bchannel(struct bc_state *bcs)
+{
+	struct cardstate *cs = bcs->cs;
+	int req, ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cs->lock, flags);
+	if (unlikely(!cs->connected)) {
+		spin_unlock_irqrestore(&cs->lock, flags);
+		gig_dbg(DEBUG_USBREQ, "%s: not connected", __func__);
+		return -ENODEV;
+	}
+
+	if (!(cs->hw.bas->basstate & (bcs->channel ? BS_B2OPEN : BS_B1OPEN))) {
+		/* channel not running: just signal common.c */
+		spin_unlock_irqrestore(&cs->lock, flags);
+		gigaset_bchannel_down(bcs);
+		return 0;
+	}
+
+	/* channel running: tell device to close it */
+	req = bcs->channel ? HD_CLOSE_B2CHANNEL : HD_CLOSE_B1CHANNEL;
+	ret = req_submit(bcs, req, 0, BAS_TIMEOUT);
+	if (ret < 0)
+		dev_err(cs->dev, "closing channel B%d failed\n",
+			bcs->channel + 1);
+
+	spin_unlock_irqrestore(&cs->lock, flags);
+	return ret;
+}
+
+/* Device Operations */
+/* ================= */
+
+/* complete_cb
+ * unqueue first command buffer from queue, waking any sleepers
+ * must be called with cs->cmdlock held
+ * parameter:
+ *	cs	controller state structure
+ */
+static void complete_cb(struct cardstate *cs)
+{
+	struct cmdbuf_t *cb = cs->cmdbuf;
+
+	/* unqueue completed buffer */
+	cs->cmdbytes -= cs->curlen;
+	gig_dbg(DEBUG_OUTPUT, "write_command: sent %u bytes, %u left",
+		cs->curlen, cs->cmdbytes);
+	if (cb->next != NULL) {
+		cs->cmdbuf = cb->next;
+		cs->cmdbuf->prev = NULL;
+		cs->curlen = cs->cmdbuf->len;
+	} else {
+		cs->cmdbuf = NULL;
+		cs->lastcmdbuf = NULL;
+		cs->curlen = 0;
+	}
+
+	if (cb->wake_tasklet)
+		tasklet_schedule(cb->wake_tasklet);
+
+	kfree(cb);
+}
+
+/* write_command_callback
+ * USB completion handler for AT command transmission
+ * called by the USB subsystem in interrupt context
+ * parameter:
+ *	urb	USB request block of completed request
+ *		urb->context = controller state structure
+ */
+static void write_command_callback(struct urb *urb)
+{
+	struct cardstate *cs = urb->context;
+	struct bas_cardstate *ucs = cs->hw.bas;
+	int status = urb->status;
+	unsigned long flags;
+
+	update_basstate(ucs, 0, BS_ATWRPEND);
+	wake_up(&ucs->waitqueue);
+
+	/* check status */
+	switch (status) {
+	case 0:					/* normal completion */
+		break;
+	case -ENOENT:			/* cancelled */
+	case -ECONNRESET:		/* cancelled (async) */
+	case -EINPROGRESS:		/* pending */
+	case -ENODEV:			/* device removed */
+	case -ESHUTDOWN:		/* device shut down */
+		/* ignore silently */
+		gig_dbg(DEBUG_USBREQ, "%s: %s",
+			__func__, get_usb_statmsg(status));
+		return;
+	default:				/* any failure */
+		if (++ucs->retry_cmd_out > BAS_RETRY) {
+			dev_warn(cs->dev,
+				 "command write: %s, "
+				 "giving up after %d retries\n",
+				 get_usb_statmsg(status),
+				 ucs->retry_cmd_out);
+			break;
+		}
+		if (ucs->basstate & BS_SUSPEND) {
+			dev_warn(cs->dev,
+				 "command write: %s, "
+				 "won't retry - suspend requested\n",
+				 get_usb_statmsg(status));
+			break;
+		}
+		if (cs->cmdbuf == NULL) {
+			dev_warn(cs->dev,
+				 "command write: %s, "
+				 "cannot retry - cmdbuf gone\n",
+				 get_usb_statmsg(status));
+			break;
+		}
+		dev_notice(cs->dev, "command write: %s, retry %d\n",
+			   get_usb_statmsg(status), ucs->retry_cmd_out);
+		if (atwrite_submit(cs, cs->cmdbuf->buf, cs->cmdbuf->len) >= 0)
+			/* resubmitted - bypass regular exit block */
+			return;
+		/* command send failed, assume base still waiting */
+		update_basstate(ucs, BS_ATREADY, 0);
+	}
+
+	spin_lock_irqsave(&cs->cmdlock, flags);
+	if (cs->cmdbuf != NULL)
+		complete_cb(cs);
+	spin_unlock_irqrestore(&cs->cmdlock, flags);
+}
+
+/* atrdy_timeout
+ * timeout routine for AT command transmission
+ * argument:
+ *	controller state structure
+ */
+static void atrdy_timeout(unsigned long data)
+{
+	struct cardstate *cs = (struct cardstate *) data;
+	struct bas_cardstate *ucs = cs->hw.bas;
+
+	dev_warn(cs->dev, "timeout waiting for HD_READY_SEND_ATDATA\n");
+
+	/* fake the missing signal - what else can I do? */
+	update_basstate(ucs, BS_ATREADY, BS_ATTIMER);
+	start_cbsend(cs);
+}
+
+/* atwrite_submit
+ * submit an HD_WRITE_ATMESSAGE command URB
+ * parameters:
+ *	cs	controller state structure
+ *	buf	buffer containing command to send
+ *	len	length of command to send
+ * return value:
+ *	0 on success
+ *	-EBUSY if another request is pending
+ *	any URB submission error code
+ */
+static int atwrite_submit(struct cardstate *cs, unsigned char *buf, int len)
+{
+	struct bas_cardstate *ucs = cs->hw.bas;
+	int rc;
+
+	gig_dbg(DEBUG_USBREQ, "-------> HD_WRITE_ATMESSAGE (%d)", len);
+
+	if (update_basstate(ucs, BS_ATWRPEND, 0) & BS_ATWRPEND) {
+		dev_err(cs->dev,
+			"could not submit HD_WRITE_ATMESSAGE: URB busy\n");
+		return -EBUSY;
+	}
+
+	ucs->dr_cmd_out.bRequestType = OUT_VENDOR_REQ;
+	ucs->dr_cmd_out.bRequest = HD_WRITE_ATMESSAGE;
+	ucs->dr_cmd_out.wValue = 0;
+	ucs->dr_cmd_out.wIndex = 0;
+	ucs->dr_cmd_out.wLength = cpu_to_le16(len);
+	usb_fill_control_urb(ucs->urb_cmd_out, ucs->udev,
+			     usb_sndctrlpipe(ucs->udev, 0),
+			     (unsigned char *) &ucs->dr_cmd_out, buf, len,
+			     write_command_callback, cs);
+	rc = usb_submit_urb(ucs->urb_cmd_out, GFP_ATOMIC);
+	if (unlikely(rc)) {
+		update_basstate(ucs, 0, BS_ATWRPEND);
+		dev_err(cs->dev, "could not submit HD_WRITE_ATMESSAGE: %s\n",
+			get_usb_rcmsg(rc));
+		return rc;
+	}
+
+	/* submitted successfully, start timeout if necessary */
+	if (!(update_basstate(ucs, BS_ATTIMER, BS_ATREADY) & BS_ATTIMER)) {
+		gig_dbg(DEBUG_OUTPUT, "setting ATREADY timeout of %d/10 secs",
+			ATRDY_TIMEOUT);
+		mod_timer(&ucs->timer_atrdy, jiffies + ATRDY_TIMEOUT * HZ / 10);
+	}
+	return 0;
+}
+
+/* start_cbsend
+ * start transmission of AT command queue if necessary
+ * parameter:
+ *	cs		controller state structure
+ * return value:
+ *	0 on success
+ *	error code < 0 on error
+ */
+static int start_cbsend(struct cardstate *cs)
+{
+	struct cmdbuf_t *cb;
+	struct bas_cardstate *ucs = cs->hw.bas;
+	unsigned long flags;
+	int rc;
+	int retval = 0;
+
+	/* check if suspend requested */
+	if (ucs->basstate & BS_SUSPEND) {
+		gig_dbg(DEBUG_OUTPUT, "suspending");
+		return -EHOSTUNREACH;
+	}
+
+	/* check if AT channel is open */
+	if (!(ucs->basstate & BS_ATOPEN)) {
+		gig_dbg(DEBUG_OUTPUT, "AT channel not open");
+		rc = req_submit(cs->bcs, HD_OPEN_ATCHANNEL, 0, BAS_TIMEOUT);
+		if (rc < 0) {
+			/* flush command queue */
+			spin_lock_irqsave(&cs->cmdlock, flags);
+			while (cs->cmdbuf != NULL)
+				complete_cb(cs);
+			spin_unlock_irqrestore(&cs->cmdlock, flags);
+		}
+		return rc;
+	}
+
+	/* try to send first command in queue */
+	spin_lock_irqsave(&cs->cmdlock, flags);
+
+	while ((cb = cs->cmdbuf) != NULL && (ucs->basstate & BS_ATREADY)) {
+		ucs->retry_cmd_out = 0;
+		rc = atwrite_submit(cs, cb->buf, cb->len);
+		if (unlikely(rc)) {
+			retval = rc;
+			complete_cb(cs);
+		}
+	}
+
+	spin_unlock_irqrestore(&cs->cmdlock, flags);
+	return retval;
+}
+
+/* gigaset_write_cmd
+ * This function is called by the device independent part of the driver
+ * to transmit an AT command string to the Gigaset device.
+ * It encapsulates the device specific method for transmission over the
+ * direct USB connection to the base.
+ * The command string is added to the queue of commands to send, and
+ * USB transmission is started if necessary.
+ * parameters:
+ *	cs		controller state structure
+ *	cb		command buffer structure
+ * return value:
+ *	number of bytes queued on success
+ *	error code < 0 on error
+ */
+static int gigaset_write_cmd(struct cardstate *cs, struct cmdbuf_t *cb)
+{
+	unsigned long flags;
+	int rc;
+
+	gigaset_dbg_buffer(cs->mstate != MS_LOCKED ?
+			   DEBUG_TRANSCMD : DEBUG_LOCKCMD,
+			   "CMD Transmit", cb->len, cb->buf);
+
+	/* translate "+++" escape sequence sent as a single separate command
+	 * into "close AT channel" command for error recovery
+	 * The next command will reopen the AT channel automatically.
+	 */
+	if (cb->len == 3 && !memcmp(cb->buf, "+++", 3)) {
+		/* If an HD_RECEIVEATDATA_ACK message remains unhandled
+		 * because of an error, the base never sends another one.
+		 * The response channel is thus effectively blocked.
+		 * Closing and reopening the AT channel does *not* clear
+		 * this condition.
+		 * As a stopgap measure, submit a zero-length AT read
+		 * before closing the AT channel. This has the undocumented
+		 * effect of triggering a new HD_RECEIVEATDATA_ACK message
+		 * from the base if necessary.
+		 * The subsequent AT channel close then discards any pending
+		 * messages.
+		 */
+		spin_lock_irqsave(&cs->lock, flags);
+		if (!(cs->hw.bas->basstate & BS_ATRDPEND)) {
+			kfree(cs->hw.bas->rcvbuf);
+			cs->hw.bas->rcvbuf = NULL;
+			cs->hw.bas->rcvbuf_size = 0;
+			cs->hw.bas->retry_cmd_in = 0;
+			atread_submit(cs, 0);
+		}
+		spin_unlock_irqrestore(&cs->lock, flags);
+
+		rc = req_submit(cs->bcs, HD_CLOSE_ATCHANNEL, 0, BAS_TIMEOUT);
+		if (cb->wake_tasklet)
+			tasklet_schedule(cb->wake_tasklet);
+		if (!rc)
+			rc = cb->len;
+		kfree(cb);
+		return rc;
+	}
+
+	spin_lock_irqsave(&cs->cmdlock, flags);
+	cb->prev = cs->lastcmdbuf;
+	if (cs->lastcmdbuf)
+		cs->lastcmdbuf->next = cb;
+	else {
+		cs->cmdbuf = cb;
+		cs->curlen = cb->len;
+	}
+	cs->cmdbytes += cb->len;
+	cs->lastcmdbuf = cb;
+	spin_unlock_irqrestore(&cs->cmdlock, flags);
+
+	spin_lock_irqsave(&cs->lock, flags);
+	if (unlikely(!cs->connected)) {
+		spin_unlock_irqrestore(&cs->lock, flags);
+		gig_dbg(DEBUG_USBREQ, "%s: not connected", __func__);
+		/* flush command queue */
+		spin_lock_irqsave(&cs->cmdlock, flags);
+		while (cs->cmdbuf != NULL)
+			complete_cb(cs);
+		spin_unlock_irqrestore(&cs->cmdlock, flags);
+		return -ENODEV;
+	}
+	rc = start_cbsend(cs);
+	spin_unlock_irqrestore(&cs->lock, flags);
+	return rc < 0 ? rc : cb->len;
+}
+
+/* gigaset_write_room
+ * tty_driver.write_room interface routine
+ * return number of characters the driver will accept to be written via
+ * gigaset_write_cmd
+ * parameter:
+ *	controller state structure
+ * return value:
+ *	number of characters
+ */
+static int gigaset_write_room(struct cardstate *cs)
+{
+	return IF_WRITEBUF;
+}
+
+/* gigaset_chars_in_buffer
+ * tty_driver.chars_in_buffer interface routine
+ * return number of characters waiting to be sent
+ * parameter:
+ *	controller state structure
+ * return value:
+ *	number of characters
+ */
+static int gigaset_chars_in_buffer(struct cardstate *cs)
+{
+	return cs->cmdbytes;
+}
+
+/* gigaset_brkchars
+ * implementation of ioctl(GIGASET_BRKCHARS)
+ * parameter:
+ *	controller state structure
+ * return value:
+ *	-EINVAL (unimplemented function)
+ */
+static int gigaset_brkchars(struct cardstate *cs, const unsigned char buf[6])
+{
+	return -EINVAL;
+}
+
+
+/* Device Initialization/Shutdown */
+/* ============================== */
+
+/* Free hardware dependent part of the B channel structure
+ * parameter:
+ *	bcs	B channel structure
+ */
+static void gigaset_freebcshw(struct bc_state *bcs)
+{
+	struct bas_bc_state *ubc = bcs->hw.bas;
+	int i;
+
+	if (!ubc)
+		return;
+
+	/* kill URBs and tasklets before freeing - better safe than sorry */
+	ubc->running = 0;
+	gig_dbg(DEBUG_INIT, "%s: killing isoc URBs", __func__);
+	for (i = 0; i < BAS_OUTURBS; ++i) {
+		usb_kill_urb(ubc->isoouturbs[i].urb);
+		usb_free_urb(ubc->isoouturbs[i].urb);
+	}
+	for (i = 0; i < BAS_INURBS; ++i) {
+		usb_kill_urb(ubc->isoinurbs[i]);
+		usb_free_urb(ubc->isoinurbs[i]);
+	}
+	tasklet_kill(&ubc->sent_tasklet);
+	tasklet_kill(&ubc->rcvd_tasklet);
+	kfree(ubc->isooutbuf);
+	kfree(ubc);
+	bcs->hw.bas = NULL;
+}
+
+/* Initialize hardware dependent part of the B channel structure
+ * parameter:
+ *	bcs	B channel structure
+ * return value:
+ *	0 on success, error code < 0 on failure
+ */
+static int gigaset_initbcshw(struct bc_state *bcs)
+{
+	int i;
+	struct bas_bc_state *ubc;
+
+	bcs->hw.bas = ubc = kmalloc(sizeof(struct bas_bc_state), GFP_KERNEL);
+	if (!ubc) {
+		pr_err("out of memory\n");
+		return -ENOMEM;
+	}
+
+	ubc->running = 0;
+	atomic_set(&ubc->corrbytes, 0);
+	spin_lock_init(&ubc->isooutlock);
+	for (i = 0; i < BAS_OUTURBS; ++i) {
+		ubc->isoouturbs[i].urb = NULL;
+		ubc->isoouturbs[i].bcs = bcs;
+	}
+	ubc->isooutdone = ubc->isooutfree = ubc->isooutovfl = NULL;
+	ubc->numsub = 0;
+	ubc->isooutbuf = kmalloc(sizeof(struct isowbuf_t), GFP_KERNEL);
+	if (!ubc->isooutbuf) {
+		pr_err("out of memory\n");
+		kfree(ubc);
+		bcs->hw.bas = NULL;
+		return -ENOMEM;
+	}
+	tasklet_init(&ubc->sent_tasklet,
+		     write_iso_tasklet, (unsigned long) bcs);
+
+	spin_lock_init(&ubc->isoinlock);
+	for (i = 0; i < BAS_INURBS; ++i)
+		ubc->isoinurbs[i] = NULL;
+	ubc->isoindone = NULL;
+	ubc->loststatus = -EINPROGRESS;
+	ubc->isoinlost = 0;
+	ubc->seqlen = 0;
+	ubc->inbyte = 0;
+	ubc->inbits = 0;
+	ubc->goodbytes = 0;
+	ubc->alignerrs = 0;
+	ubc->fcserrs = 0;
+	ubc->frameerrs = 0;
+	ubc->giants = 0;
+	ubc->runts = 0;
+	ubc->aborts = 0;
+	ubc->shared0s = 0;
+	ubc->stolen0s = 0;
+	tasklet_init(&ubc->rcvd_tasklet,
+		     read_iso_tasklet, (unsigned long) bcs);
+	return 0;
+}
+
+static void gigaset_reinitbcshw(struct bc_state *bcs)
+{
+	struct bas_bc_state *ubc = bcs->hw.bas;
+
+	bcs->hw.bas->running = 0;
+	atomic_set(&bcs->hw.bas->corrbytes, 0);
+	bcs->hw.bas->numsub = 0;
+	spin_lock_init(&ubc->isooutlock);
+	spin_lock_init(&ubc->isoinlock);
+	ubc->loststatus = -EINPROGRESS;
+}
+
+static void gigaset_freecshw(struct cardstate *cs)
+{
+	/* timers, URBs and rcvbuf are disposed of in disconnect */
+	kfree(cs->hw.bas->int_in_buf);
+	kfree(cs->hw.bas);
+	cs->hw.bas = NULL;
+}
+
+/* Initialize hardware dependent part of the cardstate structure
+ * parameter:
+ *	cs	cardstate structure
+ * return value:
+ *	0 on success, error code < 0 on failure
+ */
+static int gigaset_initcshw(struct cardstate *cs)
+{
+	struct bas_cardstate *ucs;
+
+	cs->hw.bas = ucs = kmalloc(sizeof *ucs, GFP_KERNEL);
+	if (!ucs) {
+		pr_err("out of memory\n");
+		return -ENOMEM;
+	}
+	ucs->int_in_buf = kmalloc(IP_MSGSIZE, GFP_KERNEL);
+	if (!ucs->int_in_buf) {
+		kfree(ucs);
+		pr_err("out of memory\n");
+		return -ENOMEM;
+	}
+
+	ucs->urb_cmd_in = NULL;
+	ucs->urb_cmd_out = NULL;
+	ucs->rcvbuf = NULL;
+	ucs->rcvbuf_size = 0;
+
+	spin_lock_init(&ucs->lock);
+	ucs->pending = 0;
+
+	ucs->basstate = 0;
+	setup_timer(&ucs->timer_ctrl, req_timeout, (unsigned long) cs);
+	setup_timer(&ucs->timer_atrdy, atrdy_timeout, (unsigned long) cs);
+	setup_timer(&ucs->timer_cmd_in, cmd_in_timeout, (unsigned long) cs);
+	setup_timer(&ucs->timer_int_in, int_in_resubmit, (unsigned long) cs);
+	init_waitqueue_head(&ucs->waitqueue);
+	INIT_WORK(&ucs->int_in_wq, int_in_work);
+
+	return 0;
+}
+
+/* freeurbs
+ * unlink and deallocate all URBs unconditionally
+ * caller must make sure that no commands are still in progress
+ * parameter:
+ *	cs	controller state structure
+ */
+static void freeurbs(struct cardstate *cs)
+{
+	struct bas_cardstate *ucs = cs->hw.bas;
+	struct bas_bc_state *ubc;
+	int i, j;
+
+	gig_dbg(DEBUG_INIT, "%s: killing URBs", __func__);
+	for (j = 0; j < BAS_CHANNELS; ++j) {
+		ubc = cs->bcs[j].hw.bas;
+		for (i = 0; i < BAS_OUTURBS; ++i) {
+			usb_kill_urb(ubc->isoouturbs[i].urb);
+			usb_free_urb(ubc->isoouturbs[i].urb);
+			ubc->isoouturbs[i].urb = NULL;
+		}
+		for (i = 0; i < BAS_INURBS; ++i) {
+			usb_kill_urb(ubc->isoinurbs[i]);
+			usb_free_urb(ubc->isoinurbs[i]);
+			ubc->isoinurbs[i] = NULL;
+		}
+	}
+	usb_kill_urb(ucs->urb_int_in);
+	usb_free_urb(ucs->urb_int_in);
+	ucs->urb_int_in = NULL;
+	usb_kill_urb(ucs->urb_cmd_out);
+	usb_free_urb(ucs->urb_cmd_out);
+	ucs->urb_cmd_out = NULL;
+	usb_kill_urb(ucs->urb_cmd_in);
+	usb_free_urb(ucs->urb_cmd_in);
+	ucs->urb_cmd_in = NULL;
+	usb_kill_urb(ucs->urb_ctrl);
+	usb_free_urb(ucs->urb_ctrl);
+	ucs->urb_ctrl = NULL;
+}
+
+/* gigaset_probe
+ * This function is called when a new USB device is connected.
+ * It checks whether the new device is handled by this driver.
+ */
+static int gigaset_probe(struct usb_interface *interface,
+			 const struct usb_device_id *id)
+{
+	struct usb_host_interface *hostif;
+	struct usb_device *udev = interface_to_usbdev(interface);
+	struct cardstate *cs = NULL;
+	struct bas_cardstate *ucs = NULL;
+	struct bas_bc_state *ubc;
+	struct usb_endpoint_descriptor *endpoint;
+	int i, j;
+	int rc;
+
+	gig_dbg(DEBUG_INIT,
+		"%s: Check if device matches .. (Vendor: 0x%x, Product: 0x%x)",
+		__func__, le16_to_cpu(udev->descriptor.idVendor),
+		le16_to_cpu(udev->descriptor.idProduct));
+
+	/* set required alternate setting */
+	hostif = interface->cur_altsetting;
+	if (hostif->desc.bAlternateSetting != 3) {
+		gig_dbg(DEBUG_INIT,
+			"%s: wrong alternate setting %d - trying to switch",
+			__func__, hostif->desc.bAlternateSetting);
+		if (usb_set_interface(udev, hostif->desc.bInterfaceNumber, 3)
+		    < 0) {
+			dev_warn(&udev->dev, "usb_set_interface failed, "
+				 "device %d interface %d altsetting %d\n",
+				 udev->devnum, hostif->desc.bInterfaceNumber,
+				 hostif->desc.bAlternateSetting);
+			return -ENODEV;
+		}
+		hostif = interface->cur_altsetting;
+	}
+
+	/* Reject application specific interfaces
+	 */
+	if (hostif->desc.bInterfaceClass != 255) {
+		dev_warn(&udev->dev, "%s: bInterfaceClass == %d\n",
+			 __func__, hostif->desc.bInterfaceClass);
+		return -ENODEV;
+	}
+
+	dev_info(&udev->dev,
+		 "%s: Device matched (Vendor: 0x%x, Product: 0x%x)\n",
+		 __func__, le16_to_cpu(udev->descriptor.idVendor),
+		 le16_to_cpu(udev->descriptor.idProduct));
+
+	/* allocate memory for our device state and initialize it */
+	cs = gigaset_initcs(driver, BAS_CHANNELS, 0, 0, cidmode,
+			    GIGASET_MODULENAME);
+	if (!cs)
+		return -ENODEV;
+	ucs = cs->hw.bas;
+
+	/* save off device structure ptrs for later use */
+	usb_get_dev(udev);
+	ucs->udev = udev;
+	ucs->interface = interface;
+	cs->dev = &interface->dev;
+
+	/* allocate URBs:
+	 * - one for the interrupt pipe
+	 * - three for the different uses of the default control pipe
+	 * - three for each isochronous pipe
+	 */
+	if (!(ucs->urb_int_in = usb_alloc_urb(0, GFP_KERNEL)) ||
+	    !(ucs->urb_cmd_in = usb_alloc_urb(0, GFP_KERNEL)) ||
+	    !(ucs->urb_cmd_out = usb_alloc_urb(0, GFP_KERNEL)) ||
+	    !(ucs->urb_ctrl = usb_alloc_urb(0, GFP_KERNEL)))
+		goto allocerr;
+
+	for (j = 0; j < BAS_CHANNELS; ++j) {
+		ubc = cs->bcs[j].hw.bas;
+		for (i = 0; i < BAS_OUTURBS; ++i)
+			if (!(ubc->isoouturbs[i].urb =
+			      usb_alloc_urb(BAS_NUMFRAMES, GFP_KERNEL)))
+				goto allocerr;
+		for (i = 0; i < BAS_INURBS; ++i)
+			if (!(ubc->isoinurbs[i] =
+			      usb_alloc_urb(BAS_NUMFRAMES, GFP_KERNEL)))
+				goto allocerr;
+	}
+
+	ucs->rcvbuf = NULL;
+	ucs->rcvbuf_size = 0;
+
+	/* Fill the interrupt urb and send it to the core */
+	endpoint = &hostif->endpoint[0].desc;
+	usb_fill_int_urb(ucs->urb_int_in, udev,
+			 usb_rcvintpipe(udev,
+					usb_endpoint_num(endpoint)),
+			 ucs->int_in_buf, IP_MSGSIZE, read_int_callback, cs,
+			 endpoint->bInterval);
+	rc = usb_submit_urb(ucs->urb_int_in, GFP_KERNEL);
+	if (rc != 0) {
+		dev_err(cs->dev, "could not submit interrupt URB: %s\n",
+			get_usb_rcmsg(rc));
+		goto error;
+	}
+	ucs->retry_int_in = 0;
+
+	/* tell the device that the driver is ready */
+	rc = req_submit(cs->bcs, HD_DEVICE_INIT_ACK, 0, 0);
+	if (rc != 0)
+		goto error;
+
+	/* tell common part that the device is ready */
+	if (startmode == SM_LOCKED)
+		cs->mstate = MS_LOCKED;
+
+	/* save address of controller structure */
+	usb_set_intfdata(interface, cs);
+
+	rc = gigaset_start(cs);
+	if (rc < 0)
+		goto error;
+
+	return 0;
+
+allocerr:
+	dev_err(cs->dev, "could not allocate URBs\n");
+	rc = -ENOMEM;
+error:
+	freeurbs(cs);
+	usb_set_intfdata(interface, NULL);
+	usb_put_dev(udev);
+	gigaset_freecs(cs);
+	return rc;
+}
+
+/* gigaset_disconnect
+ * This function is called when the Gigaset base is unplugged.
+ */
+static void gigaset_disconnect(struct usb_interface *interface)
+{
+	struct cardstate *cs;
+	struct bas_cardstate *ucs;
+	int j;
+
+	cs = usb_get_intfdata(interface);
+
+	ucs = cs->hw.bas;
+
+	dev_info(cs->dev, "disconnecting Gigaset base\n");
+
+	/* mark base as not ready, all channels disconnected */
+	ucs->basstate = 0;
+
+	/* tell LL all channels are down */
+	for (j = 0; j < BAS_CHANNELS; ++j)
+		gigaset_bchannel_down(cs->bcs + j);
+
+	/* stop driver (common part) */
+	gigaset_stop(cs);
+
+	/* stop delayed work and URBs, free ressources */
+	del_timer_sync(&ucs->timer_ctrl);
+	del_timer_sync(&ucs->timer_atrdy);
+	del_timer_sync(&ucs->timer_cmd_in);
+	del_timer_sync(&ucs->timer_int_in);
+	cancel_work_sync(&ucs->int_in_wq);
+	freeurbs(cs);
+	usb_set_intfdata(interface, NULL);
+	kfree(ucs->rcvbuf);
+	ucs->rcvbuf = NULL;
+	ucs->rcvbuf_size = 0;
+	usb_put_dev(ucs->udev);
+	ucs->interface = NULL;
+	ucs->udev = NULL;
+	cs->dev = NULL;
+	gigaset_freecs(cs);
+}
+
+/* gigaset_suspend
+ * This function is called before the USB connection is suspended
+ * or before the USB device is reset.
+ * In the latter case, message == PMSG_ON.
+ */
+static int gigaset_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct cardstate *cs = usb_get_intfdata(intf);
+	struct bas_cardstate *ucs = cs->hw.bas;
+	int rc;
+
+	/* set suspend flag; this stops AT command/response traffic */
+	if (update_basstate(ucs, BS_SUSPEND, 0) & BS_SUSPEND) {
+		gig_dbg(DEBUG_SUSPEND, "already suspended");
+		return 0;
+	}
+
+	/* wait a bit for blocking conditions to go away */
+	rc = wait_event_timeout(ucs->waitqueue,
+				!(ucs->basstate &
+				  (BS_B1OPEN | BS_B2OPEN | BS_ATRDPEND | BS_ATWRPEND)),
+				BAS_TIMEOUT * HZ / 10);
+	gig_dbg(DEBUG_SUSPEND, "wait_event_timeout() -> %d", rc);
+
+	/* check for conditions preventing suspend */
+	if (ucs->basstate & (BS_B1OPEN | BS_B2OPEN | BS_ATRDPEND | BS_ATWRPEND)) {
+		dev_warn(cs->dev, "cannot suspend:\n");
+		if (ucs->basstate & BS_B1OPEN)
+			dev_warn(cs->dev, " B channel 1 open\n");
+		if (ucs->basstate & BS_B2OPEN)
+			dev_warn(cs->dev, " B channel 2 open\n");
+		if (ucs->basstate & BS_ATRDPEND)
+			dev_warn(cs->dev, " receiving AT reply\n");
+		if (ucs->basstate & BS_ATWRPEND)
+			dev_warn(cs->dev, " sending AT command\n");
+		update_basstate(ucs, 0, BS_SUSPEND);
+		return -EBUSY;
+	}
+
+	/* close AT channel if open */
+	if (ucs->basstate & BS_ATOPEN) {
+		gig_dbg(DEBUG_SUSPEND, "closing AT channel");
+		rc = req_submit(cs->bcs, HD_CLOSE_ATCHANNEL, 0, 0);
+		if (rc) {
+			update_basstate(ucs, 0, BS_SUSPEND);
+			return rc;
+		}
+		wait_event_timeout(ucs->waitqueue, !ucs->pending,
+				   BAS_TIMEOUT * HZ / 10);
+		/* in case of timeout, proceed anyway */
+	}
+
+	/* kill all URBs and delayed work that might still be pending */
+	usb_kill_urb(ucs->urb_ctrl);
+	usb_kill_urb(ucs->urb_int_in);
+	del_timer_sync(&ucs->timer_ctrl);
+	del_timer_sync(&ucs->timer_atrdy);
+	del_timer_sync(&ucs->timer_cmd_in);
+	del_timer_sync(&ucs->timer_int_in);
+
+	/* don't try to cancel int_in_wq from within reset as it
+	 * might be the one requesting the reset
+	 */
+	if (message.event != PM_EVENT_ON)
+		cancel_work_sync(&ucs->int_in_wq);
+
+	gig_dbg(DEBUG_SUSPEND, "suspend complete");
+	return 0;
+}
+
+/* gigaset_resume
+ * This function is called after the USB connection has been resumed.
+ */
+static int gigaset_resume(struct usb_interface *intf)
+{
+	struct cardstate *cs = usb_get_intfdata(intf);
+	struct bas_cardstate *ucs = cs->hw.bas;
+	int rc;
+
+	/* resubmit interrupt URB for spontaneous messages from base */
+	rc = usb_submit_urb(ucs->urb_int_in, GFP_KERNEL);
+	if (rc) {
+		dev_err(cs->dev, "could not resubmit interrupt URB: %s\n",
+			get_usb_rcmsg(rc));
+		return rc;
+	}
+	ucs->retry_int_in = 0;
+
+	/* clear suspend flag to reallow activity */
+	update_basstate(ucs, 0, BS_SUSPEND);
+
+	gig_dbg(DEBUG_SUSPEND, "resume complete");
+	return 0;
+}
+
+/* gigaset_pre_reset
+ * This function is called before the USB connection is reset.
+ */
+static int gigaset_pre_reset(struct usb_interface *intf)
+{
+	/* handle just like suspend */
+	return gigaset_suspend(intf, PMSG_ON);
+}
+
+/* gigaset_post_reset
+ * This function is called after the USB connection has been reset.
+ */
+static int gigaset_post_reset(struct usb_interface *intf)
+{
+	/* FIXME: send HD_DEVICE_INIT_ACK? */
+
+	/* resume operations */
+	return gigaset_resume(intf);
+}
+
+
+static const struct gigaset_ops gigops = {
+	gigaset_write_cmd,
+	gigaset_write_room,
+	gigaset_chars_in_buffer,
+	gigaset_brkchars,
+	gigaset_init_bchannel,
+	gigaset_close_bchannel,
+	gigaset_initbcshw,
+	gigaset_freebcshw,
+	gigaset_reinitbcshw,
+	gigaset_initcshw,
+	gigaset_freecshw,
+	gigaset_set_modem_ctrl,
+	gigaset_baud_rate,
+	gigaset_set_line_ctrl,
+	gigaset_isoc_send_skb,
+	gigaset_isoc_input,
+};
+
+/* bas_gigaset_init
+ * This function is called after the kernel module is loaded.
+ */
+static int __init bas_gigaset_init(void)
+{
+	int result;
+
+	/* allocate memory for our driver state and initialize it */
+	driver = gigaset_initdriver(GIGASET_MINOR, GIGASET_MINORS,
+				    GIGASET_MODULENAME, GIGASET_DEVNAME,
+				    &gigops, THIS_MODULE);
+	if (driver == NULL)
+		goto error;
+
+	/* register this driver with the USB subsystem */
+	result = usb_register(&gigaset_usb_driver);
+	if (result < 0) {
+		pr_err("error %d registering USB driver\n", -result);
+		goto error;
+	}
+
+	pr_info(DRIVER_DESC "\n");
+	return 0;
+
+error:
+	if (driver)
+		gigaset_freedriver(driver);
+	driver = NULL;
+	return -1;
+}
+
+/* bas_gigaset_exit
+ * This function is called before the kernel module is unloaded.
+ */
+static void __exit bas_gigaset_exit(void)
+{
+	struct bas_cardstate *ucs;
+	int i;
+
+	gigaset_blockdriver(driver); /* => probe will fail
+				      * => no gigaset_start any more
+				      */
+
+	/* stop all connected devices */
+	for (i = 0; i < driver->minors; i++) {
+		if (gigaset_shutdown(driver->cs + i) < 0)
+			continue;		/* no device */
+		/* from now on, no isdn callback should be possible */
+
+		/* close all still open channels */
+		ucs = driver->cs[i].hw.bas;
+		if (ucs->basstate & BS_B1OPEN) {
+			gig_dbg(DEBUG_INIT, "closing B1 channel");
+			usb_control_msg(ucs->udev,
+					usb_sndctrlpipe(ucs->udev, 0),
+					HD_CLOSE_B1CHANNEL, OUT_VENDOR_REQ,
+					0, 0, NULL, 0, BAS_TIMEOUT);
+		}
+		if (ucs->basstate & BS_B2OPEN) {
+			gig_dbg(DEBUG_INIT, "closing B2 channel");
+			usb_control_msg(ucs->udev,
+					usb_sndctrlpipe(ucs->udev, 0),
+					HD_CLOSE_B2CHANNEL, OUT_VENDOR_REQ,
+					0, 0, NULL, 0, BAS_TIMEOUT);
+		}
+		if (ucs->basstate & BS_ATOPEN) {
+			gig_dbg(DEBUG_INIT, "closing AT channel");
+			usb_control_msg(ucs->udev,
+					usb_sndctrlpipe(ucs->udev, 0),
+					HD_CLOSE_ATCHANNEL, OUT_VENDOR_REQ,
+					0, 0, NULL, 0, BAS_TIMEOUT);
+		}
+		ucs->basstate = 0;
+	}
+
+	/* deregister this driver with the USB subsystem */
+	usb_deregister(&gigaset_usb_driver);
+	/* this will call the disconnect-callback */
+	/* from now on, no disconnect/probe callback should be running */
+
+	gigaset_freedriver(driver);
+	driver = NULL;
+}
+
+
+module_init(bas_gigaset_init);
+module_exit(bas_gigaset_exit);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");