These changes are the raw update to linux-4.4.6-rt14. Kernel sources

are taken from kernel.org, and rt patch from the rt wiki download page.

During the rebasing, the following patch collided:

Force tick interrupt and get rid of softirq magic(I70131fb85).

Collisions have been removed because its logic was found on the
source already.

Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>

3 files changed, 53 insertions, 70 deletions

diff --git a/kernel/Documentation/serial/driver b/kernel/Documentation/serial/driver
index c415b0ef4..379468e12 100644
--- a/kernel/Documentation/serial/driver
+++ b/kernel/Documentation/serial/driver
@@ -439,11 +439,13 @@ Modem control lines via GPIO
 
 Some helpers are provided in order to set/get modem control lines via GPIO.
 
-mctrl_gpio_init(dev, idx):
+mctrl_gpio_init(port, idx):
 	This will get the {cts,rts,...}-gpios from device tree if they are
 	present and request them, set direction etc, and return an
 	allocated structure. devm_* functions are used, so there's no need
 	to call mctrl_gpio_free().
+	As this sets up the irq handling make sure to not handle changes to the
+	gpio input lines in your driver, too.
 
 mctrl_gpio_free(dev, gpios):
 	This will free the requested gpios in mctrl_gpio_init().
@@ -458,3 +460,9 @@ mctrl_gpio_set(gpios, mctrl):
 
 mctrl_gpio_get(gpios, mctrl):
 	This will update mctrl with the gpios values.
+
+mctrl_gpio_enable_ms(gpios):
+	Enables irqs and handling of changes to the ms lines.
+
+mctrl_gpio_disable_ms(gpios):
+	Disables irqs and handling of changes to the ms lines.
diff --git a/kernel/Documentation/serial/serial-rs485.txt b/kernel/Documentation/serial/serial-rs485.txt
index 39dac9542..2253b8b45 100644
--- a/kernel/Documentation/serial/serial-rs485.txt
+++ b/kernel/Documentation/serial/serial-rs485.txt
@@ -33,50 +33,10 @@
    the values given by the device tree.
 
    Any driver for devices capable of working both as RS232 and RS485 should
-   provide at least the following ioctls:
-
-    - TIOCSRS485 (typically associated with number 0x542F). This ioctl is used
-      to enable/disable RS485 mode from user-space
-
-    - TIOCGRS485 (typically associated with number 0x542E). This ioctl is used
-      to get RS485 mode from kernel-space (i.e., driver) to user-space.
-
-   In other words, the serial driver should contain a code similar to the next
-   one:
-
-	static struct uart_ops atmel_pops = {
-		/* ... */
-		.ioctl		= handle_ioctl,
-	};
-
-	static int handle_ioctl(struct uart_port *port,
-		unsigned int cmd,
-		unsigned long arg)
-	{
-		struct serial_rs485 rs485conf;
-
-		switch (cmd) {
-		case TIOCSRS485:
-			if (copy_from_user(&rs485conf,
-				(struct serial_rs485 *) arg,
-				sizeof(rs485conf)))
-					return -EFAULT;
-
-			/* ... */
-			break;
-
-		case TIOCGRS485:
-			if (copy_to_user((struct serial_rs485 *) arg,
-				...,
-				sizeof(rs485conf)))
-					return -EFAULT;
-			/* ... */
-			break;
-
-		/* ... */
-		}
-	}
-
+   implement the rs485_config callback in the uart_port structure. The
+   serial_core calls rs485_config to do the device specific part in response
+   to TIOCSRS485 and TIOCGRS485 ioctls (see below). The rs485_config callback
+   receives a pointer to struct serial_rs485.
 
 4. USAGE FROM USER-LEVEL
 
@@ -85,7 +45,7 @@
 
 	#include <linux/serial.h>
 
-	/* Driver-specific ioctls: */
+	/* RS485 ioctls: */
 	#define TIOCGRS485      0x542E
 	#define TIOCSRS485      0x542F
 
diff --git a/kernel/Documentation/serial/tty.txt b/kernel/Documentation/serial/tty.txt
index dbe6623fe..bc3842dc3 100644
--- a/kernel/Documentation/serial/tty.txt
+++ b/kernel/Documentation/serial/tty.txt
@@ -4,9 +4,6 @@
 Your guide to the ancient and twisted locking policies of the tty layer and
 the warped logic behind them. Beware all ye who read on.
 
-FIXME: still need to work out the full set of BKL assumptions and document
-them so they can eventually be killed off.
-
 
 Line Discipline
 ---------------
@@ -42,8 +39,13 @@ TTY side interfaces:
 open()		-	Called when the line discipline is attached to
 			the terminal. No other call into the line
 			discipline for this tty will occur until it
-			completes successfully. Returning an error will
-			prevent the ldisc from being attached. Can sleep.
+			completes successfully. Should initialize any
+			state needed by the ldisc, and set receive_room
+			in the tty_struct to the maximum amount of data
+			the line discipline is willing to accept from the
+			driver with a single call to receive_buf().
+			Returning an error will prevent the ldisc from
+			being attached. Can sleep.
 
 close()		-	This is called on a terminal when the line
 			discipline is being unplugged. At the point of
@@ -55,9 +57,16 @@ hangup()	-	Called when the tty line is hung up.
 			No further calls into the ldisc code will occur.
 			The return value is ignored. Can sleep.
 
-write()		-	A process is writing data through the line
-			discipline.  Multiple write calls are serialized
-			by the tty layer for the ldisc.  May sleep. 
+read()		-	(optional) A process requests reading data from
+			the line. Multiple read calls may occur in parallel
+			and the ldisc must deal with serialization issues.
+			If not defined, the process will receive an EIO
+			error. May sleep.
+
+write()		-	(optional) A process requests writing data to the
+			line. Multiple write calls are serialized by the
+			tty layer for the ldisc. If not defined, the
+			process will receive an EIO error. May sleep.
 
 flush_buffer()	-	(optional) May be called at any point between
 			open and close, and instructs the line discipline
@@ -72,27 +81,33 @@ set_termios()	-	(optional) Called on termios structure changes.
 			termios semaphore so allowed to sleep. Serialized
 			against itself only.
 
-read()		-	Move data from the line discipline to the user.
-			Multiple read calls may occur in parallel and the
-			ldisc must deal with serialization issues. May 
-			sleep.
-
-poll()		-	Check the status for the poll/select calls. Multiple
-			poll calls may occur in parallel. May sleep.
+poll()		-	(optional) Check the status for the poll/select
+			calls. Multiple poll calls may occur in parallel.
+			May sleep.
 
-ioctl()		-	Called when an ioctl is handed to the tty layer
-			that might be for the ldisc. Multiple ioctl calls
-			may occur in parallel. May sleep. 
+ioctl()		-	(optional) Called when an ioctl is handed to the
+			tty layer that might be for the ldisc. Multiple
+			ioctl calls may occur in parallel. May sleep.
 
-compat_ioctl()	-	Called when a 32 bit ioctl is handed to the tty layer
-			that might be for the ldisc. Multiple ioctl calls
-			may occur in parallel. May sleep.
+compat_ioctl()	-	(optional) Called when a 32 bit ioctl is handed
+			to the tty layer that might be for the ldisc.
+			Multiple ioctl calls may occur in parallel.
+			May sleep.
 
 Driver Side Interfaces:
 
-receive_buf()	-	Hand buffers of bytes from the driver to the ldisc
-			for processing. Semantics currently rather
-			mysterious 8(
+receive_buf()	-	(optional) Called by the low-level driver to hand
+			a buffer of received bytes to the ldisc for
+			processing. The number of bytes is guaranteed not
+			to exceed the current value of tty->receive_room.
+			All bytes must be processed.
+
+receive_buf2()	-	(optional) Called by the low-level driver to hand
+			a buffer of received bytes to the ldisc for
+			processing. Returns the number of bytes processed.
+
+			If both receive_buf() and receive_buf2() are
+			defined, receive_buf2() should be preferred.
 
 write_wakeup()	-	May be called at any point between open and close.
 			The TTY_DO_WRITE_WAKEUP flag indicates if a call