Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

1 files changed, 19 insertions, 5 deletions

diff --git a/kernel/include/linux/serio.h b/kernel/include/linux/serio.h
index df4ab5de1..c733cff44 100644
--- a/kernel/include/linux/serio.h
+++ b/kernel/include/linux/serio.h
@@ -31,7 +31,8 @@ struct serio {
 
 	struct serio_device_id id;
 
-	spinlock_t lock;		/* protects critical sections from port's interrupt handler */
+	/* Protects critical sections from port's interrupt handler */
+	spinlock_t lock;
 
 	int (*write)(struct serio *, unsigned char);
 	int (*open)(struct serio *);
@@ -40,16 +41,29 @@ struct serio {
 	void (*stop)(struct serio *);
 
 	struct serio *parent;
-	struct list_head child_node;	/* Entry in parent->children list */
+	/* Entry in parent->children list */
+	struct list_head child_node;
 	struct list_head children;
-	unsigned int depth;		/* level of nesting in serio hierarchy */
+	/* Level of nesting in serio hierarchy */
+	unsigned int depth;
 
-	struct serio_driver *drv;	/* accessed from interrupt, must be protected by serio->lock and serio->sem */
-	struct mutex drv_mutex;		/* protects serio->drv so attributes can pin driver */
+	/*
+	 * serio->drv is accessed from interrupt handlers; when modifying
+	 * caller should acquire serio->drv_mutex and serio->lock.
+	 */
+	struct serio_driver *drv;
+	/* Protects serio->drv so attributes can pin current driver */
+	struct mutex drv_mutex;
 
 	struct device dev;
 
 	struct list_head node;
+
+	/*
+	 * For use by PS/2 layer when several ports share hardware and
+	 * may get indigestion when exposed to concurrent access (i8042).
+	 */
+	struct mutex *ps2_cmd_mutex;
 };
 #define to_serio_port(d)	container_of(d, struct serio, dev)