diff options
Diffstat (limited to 'kernel/drivers/net/wimax/i2400m/usb-tx.c')
| -rw-r--r-- | kernel/drivers/net/wimax/i2400m/usb-tx.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/kernel/drivers/net/wimax/i2400m/usb-tx.c b/kernel/drivers/net/wimax/i2400m/usb-tx.c new file mode 100644 index 000000000..99ef81b3d --- /dev/null +++ b/kernel/drivers/net/wimax/i2400m/usb-tx.c @@ -0,0 +1,273 @@ +/* + * Intel Wireless WiMAX Connection 2400m + * USB specific TX handling + * + * + * Copyright (C) 2007-2008 Intel Corporation. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * + * Intel Corporation <linux-wimax@intel.com> + * Yanir Lubetkin <yanirx.lubetkin@intel.com> + * - Initial implementation + * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> + * - Split transport/device specific + * + * + * Takes the TX messages in the i2400m's driver TX FIFO and sends them + * to the device until there are no more. + * + * If we fail sending the message, we just drop it. There isn't much + * we can do at this point. We could also retry, but the USB stack has + * already retried and still failed, so there is not much of a + * point. As well, most of the traffic is network, which has recovery + * methods for dropped packets. + * + * For sending we just obtain a FIFO buffer to send, send it to the + * USB bulk out, tell the TX FIFO code we have sent it; query for + * another one, etc... until done. + * + * We use a thread so we can call usb_autopm_enable() and + * usb_autopm_disable() for each transaction; this way when the device + * goes idle, it will suspend. It also has less overhead than a + * dedicated workqueue, as it is being used for a single task. + * + * ROADMAP + * + * i2400mu_tx_setup() + * i2400mu_tx_release() + * + * i2400mu_bus_tx_kick() - Called by the tx.c code when there + * is new data in the FIFO. + * i2400mu_txd() + * i2400m_tx_msg_get() + * i2400m_tx_msg_sent() + */ +#include "i2400m-usb.h" + + +#define D_SUBMODULE tx +#include "usb-debug-levels.h" + + +/* + * Get the next TX message in the TX FIFO and send it to the device + * + * Note that any iteration consumes a message to be sent, no matter if + * it succeeds or fails (we have no real way to retry or complain). + * + * Return: 0 if ok, < 0 errno code on hard error. + */ +static +int i2400mu_tx(struct i2400mu *i2400mu, struct i2400m_msg_hdr *tx_msg, + size_t tx_msg_size) +{ + int result = 0; + struct i2400m *i2400m = &i2400mu->i2400m; + struct device *dev = &i2400mu->usb_iface->dev; + int usb_pipe, sent_size, do_autopm; + struct usb_endpoint_descriptor *epd; + + d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu); + do_autopm = atomic_read(&i2400mu->do_autopm); + result = do_autopm ? + usb_autopm_get_interface(i2400mu->usb_iface) : 0; + if (result < 0) { + dev_err(dev, "TX: can't get autopm: %d\n", result); + do_autopm = 0; + } + epd = usb_get_epd(i2400mu->usb_iface, i2400mu->endpoint_cfg.bulk_out); + usb_pipe = usb_sndbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress); +retry: + result = usb_bulk_msg(i2400mu->usb_dev, usb_pipe, + tx_msg, tx_msg_size, &sent_size, 200); + usb_mark_last_busy(i2400mu->usb_dev); + switch (result) { + case 0: + if (sent_size != tx_msg_size) { /* Too short? drop it */ + dev_err(dev, "TX: short write (%d B vs %zu " + "expected)\n", sent_size, tx_msg_size); + result = -EIO; + } + break; + case -EPIPE: + /* + * Stall -- maybe the device is choking with our + * requests. Clear it and give it some time. If they + * happen to often, it might be another symptom, so we + * reset. + * + * No error handling for usb_clear_halt(0; if it + * works, the retry works; if it fails, this switch + * does the error handling for us. + */ + if (edc_inc(&i2400mu->urb_edc, + 10 * EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) { + dev_err(dev, "BM-CMD: too many stalls in " + "URB; resetting device\n"); + usb_queue_reset_device(i2400mu->usb_iface); + /* fallthrough */ + } else { + usb_clear_halt(i2400mu->usb_dev, usb_pipe); + msleep(10); /* give the device some time */ + goto retry; + } + case -EINVAL: /* while removing driver */ + case -ENODEV: /* dev disconnect ... */ + case -ENOENT: /* just ignore it */ + case -ESHUTDOWN: /* and exit */ + case -ECONNRESET: + result = -ESHUTDOWN; + break; + default: /* Some error? */ + if (edc_inc(&i2400mu->urb_edc, + EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) { + dev_err(dev, "TX: maximum errors in URB " + "exceeded; resetting device\n"); + usb_queue_reset_device(i2400mu->usb_iface); + } else { + dev_err(dev, "TX: cannot send URB; retrying. " + "tx_msg @%zu %zu B [%d sent]: %d\n", + (void *) tx_msg - i2400m->tx_buf, + tx_msg_size, sent_size, result); + goto retry; + } + } + if (do_autopm) + usb_autopm_put_interface(i2400mu->usb_iface); + d_fnend(4, dev, "(i2400mu %p) = result\n", i2400mu); + return result; +} + + +/* + * Get the next TX message in the TX FIFO and send it to the device + * + * Note we exit the loop if i2400mu_tx() fails; that function only + * fails on hard error (failing to tx a buffer not being one of them, + * see its doc). + * + * Return: 0 + */ +static +int i2400mu_txd(void *_i2400mu) +{ + struct i2400mu *i2400mu = _i2400mu; + struct i2400m *i2400m = &i2400mu->i2400m; + struct device *dev = &i2400mu->usb_iface->dev; + struct i2400m_msg_hdr *tx_msg; + size_t tx_msg_size; + unsigned long flags; + + d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu); + + spin_lock_irqsave(&i2400m->tx_lock, flags); + BUG_ON(i2400mu->tx_kthread != NULL); + i2400mu->tx_kthread = current; + spin_unlock_irqrestore(&i2400m->tx_lock, flags); + + while (1) { + d_printf(2, dev, "TX: waiting for messages\n"); + tx_msg = NULL; + wait_event_interruptible( + i2400mu->tx_wq, + (kthread_should_stop() /* check this first! */ + || (tx_msg = i2400m_tx_msg_get(i2400m, &tx_msg_size))) + ); + if (kthread_should_stop()) + break; + WARN_ON(tx_msg == NULL); /* should not happen...*/ + d_printf(2, dev, "TX: submitting %zu bytes\n", tx_msg_size); + d_dump(5, dev, tx_msg, tx_msg_size); + /* Yeah, we ignore errors ... not much we can do */ + i2400mu_tx(i2400mu, tx_msg, tx_msg_size); + i2400m_tx_msg_sent(i2400m); /* ack it, advance the FIFO */ + } + + spin_lock_irqsave(&i2400m->tx_lock, flags); + i2400mu->tx_kthread = NULL; + spin_unlock_irqrestore(&i2400m->tx_lock, flags); + + d_fnend(4, dev, "(i2400mu %p)\n", i2400mu); + return 0; +} + + +/* + * i2400m TX engine notifies us that there is data in the FIFO ready + * for TX + * + * If there is a URB in flight, don't do anything; when it finishes, + * it will see there is data in the FIFO and send it. Else, just + * submit a write. + */ +void i2400mu_bus_tx_kick(struct i2400m *i2400m) +{ + struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m); + struct device *dev = &i2400mu->usb_iface->dev; + + d_fnstart(3, dev, "(i2400m %p) = void\n", i2400m); + wake_up_all(&i2400mu->tx_wq); + d_fnend(3, dev, "(i2400m %p) = void\n", i2400m); +} + + +int i2400mu_tx_setup(struct i2400mu *i2400mu) +{ + int result = 0; + struct i2400m *i2400m = &i2400mu->i2400m; + struct device *dev = &i2400mu->usb_iface->dev; + struct wimax_dev *wimax_dev = &i2400m->wimax_dev; + struct task_struct *kthread; + + kthread = kthread_run(i2400mu_txd, i2400mu, "%s-tx", + wimax_dev->name); + /* the kthread function sets i2400mu->tx_thread */ + if (IS_ERR(kthread)) { + result = PTR_ERR(kthread); + dev_err(dev, "TX: cannot start thread: %d\n", result); + } + return result; +} + +void i2400mu_tx_release(struct i2400mu *i2400mu) +{ + unsigned long flags; + struct i2400m *i2400m = &i2400mu->i2400m; + struct device *dev = i2400m_dev(i2400m); + struct task_struct *kthread; + + spin_lock_irqsave(&i2400m->tx_lock, flags); + kthread = i2400mu->tx_kthread; + i2400mu->tx_kthread = NULL; + spin_unlock_irqrestore(&i2400m->tx_lock, flags); + if (kthread) + kthread_stop(kthread); + else + d_printf(1, dev, "TX: kthread had already exited\n"); +} |