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, 11 insertions, 11 deletions

diff --git a/kernel/drivers/regulator/core.c b/kernel/drivers/regulator/core.c
index 73b768335..732ac71b8 100644
--- a/kernel/drivers/regulator/core.c
+++ b/kernel/drivers/regulator/core.c
@@ -132,24 +132,24 @@ static bool have_full_constraints(void)
 	return has_full_constraints || of_have_populated_dt();
 }
 
+static inline struct regulator_dev *rdev_get_supply(struct regulator_dev *rdev)
+{
+	if (rdev && rdev->supply)
+		return rdev->supply->rdev;
+
+	return NULL;
+}
+
 /**
  * regulator_lock_supply - lock a regulator and its supplies
  * @rdev:         regulator source
  */
 static void regulator_lock_supply(struct regulator_dev *rdev)
 {
-	struct regulator *supply;
-	int i = 0;
-
-	while (1) {
-		mutex_lock_nested(&rdev->mutex, i++);
-		supply = rdev->supply;
-
-		if (!rdev->supply)
-			return;
+	int i;
 
-		rdev = supply->rdev;
-	}
+	for (i = 0; rdev; rdev = rdev_get_supply(rdev), i++)
+		mutex_lock_nested(&rdev->mutex, i);
 }
 
 /**