Patch "regulator: Only enable disabled regulators on resume" has been added to the 3.19-stable tree

[<gregkh@xxxxxxxxxxxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    regulator: Only enable disabled regulators on resume

to the 3.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     regulator-only-enable-disabled-regulators-on-resume.patch
and it can be found in the queue-3.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From 0548bf4f5ad6fc3bd93c4940fa48078b34609682 Mon Sep 17 00:00:00 2001
From: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>
Date: Mon, 2 Mar 2015 21:40:39 +0100
Subject: regulator: Only enable disabled regulators on resume

From: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>

commit 0548bf4f5ad6fc3bd93c4940fa48078b34609682 upstream.

The _regulator_do_enable() call ought to be a no-op when called on an
already-enabled regulator.  However, as an optimization
_regulator_enable() doesn't call _regulator_do_enable() on an already
enabled regulator.  That means we never test the case of calling
_regulator_do_enable() during normal usage and there may be hidden
bugs or warnings.  We have seen warnings issued by the tps65090 driver
and bugs when using the GPIO enable pin.

Let's match the same optimization that _regulator_enable() in
regulator_suspend_finish().  That may speed up suspend/resume and also
avoids exposing hidden bugs.

[Use much clearer commit message from Doug Anderson]

Signed-off-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/regulator/core.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -3856,9 +3856,11 @@ int regulator_suspend_finish(void)
 	list_for_each_entry(rdev, &regulator_list, list) {
 		mutex_lock(&rdev->mutex);
 		if (rdev->use_count > 0  || rdev->constraints->always_on) {
-			error = _regulator_do_enable(rdev);
-			if (error)
-				ret = error;
+			if (!_regulator_is_enabled(rdev)) {
+				error = _regulator_do_enable(rdev);
+				if (error)
+					ret = error;
+			}
 		} else {
 			if (!have_full_constraints())
 				goto unlock;


Patches currently in stable-queue which might be from javier.martinez@xxxxxxxxxxxxxxx are

queue-3.19/regulator-only-enable-disabled-regulators-on-resume.patch
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