android-5.4/UPSTREAM-regulator-core-Don-t-try-to-remove-device-links-if-add-failed.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Saravana Kannan <saravanak@google.com>
Date: Thu, 14 Nov 2019 16:04:38 -0800
Subject: UPSTREAM: regulator: core: Don't try to remove device links if add
 failed

device_link_add() might not always succeed depending on the type of
device link and the rest of the dependencies in the system. If
device_link_add() didn't succeed, then we shouldn't try to remove the
link later on as it might remove a link someone else created.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20191115000438.45970-1-saravanak@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>
(cherry-picked from b59b654478093fa429ad4c7897ae29f201146a00)
Change-Id: I6cffa3ca884b74122307931e8f6615f31c33ef55
---
 drivers/regulator/core.c     | 8 ++++++--
 drivers/regulator/internal.h | 1 +
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 1dba0bdf3762..fc91952c4127 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1846,6 +1846,7 @@ struct regulator *_regulator_get(struct device *dev, const char *id,
 	struct regulator_dev *rdev;
 	struct regulator *regulator;
 	const char *devname = dev ? dev_name(dev) : "deviceless";
+	struct device_link *link;
 	int ret;
 
 	if (get_type >= MAX_GET_TYPE) {
@@ -1953,7 +1954,9 @@ struct regulator *_regulator_get(struct device *dev, const char *id,
 			rdev->use_count = 0;
 	}
 
-	device_link_add(dev, &rdev->dev, DL_FLAG_STATELESS);
+	link = device_link_add(dev, &rdev->dev, DL_FLAG_STATELESS);
+	if (!IS_ERR_OR_NULL(link))
+		regulator->device_link = true;
 
 	return regulator;
 }
@@ -2048,7 +2051,8 @@ static void _regulator_put(struct regulator *regulator)
 	debugfs_remove_recursive(regulator->debugfs);
 
 	if (regulator->dev) {
-		device_link_remove(regulator->dev, &rdev->dev);
+		if (regulator->device_link)
+			device_link_remove(regulator->dev, &rdev->dev);
 
 		/* remove any sysfs entries */
 		sysfs_remove_link(&rdev->dev.kobj, regulator->supply_name);
diff --git a/drivers/regulator/internal.h b/drivers/regulator/internal.h
index 83ae442f515b..2391b565ef11 100644
--- a/drivers/regulator/internal.h
+++ b/drivers/regulator/internal.h
@@ -36,6 +36,7 @@ struct regulator {
 	struct list_head list;
 	unsigned int always_on:1;
 	unsigned int bypass:1;
+	unsigned int device_link:1;
 	int uA_load;
 	unsigned int enable_count;
 	unsigned int deferred_disables;