FAILED: patch "[PATCH] hwrng: stm32 - Fix runtime PM cleanup on registration failure" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] hwrng: stm32 - Fix runtime PM cleanup on registration failure" failed to apply to 6.6-stable tree

[gregkh]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 1163a476a568f6c0f852d469c8e4c5a5f805adac
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026090319-throng-sprain-3ab3@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 1163a476a568f6c0f852d469c8e4c5a5f805adac Mon Sep 17 00:00:00 2001
From: Can Peng <pengcan@kylinos.cn>
Date: Sat, 18 Jul 2026 11:29:37 +0800
Subject: [PATCH] hwrng: stm32 - Fix runtime PM cleanup on registration failure

stm32_rng_probe() enables autosuspend and runtime PM before registering the
hwrng. If devm_hwrng_register() fails, probe returns with runtime PM left
enabled and autosuspend still selected.

The remove callback also only disables runtime PM and does not undo
pm_runtime_use_autosuspend().

Use devm_pm_runtime_enable() so runtime PM is unwound automatically on
probe failure and driver detach. Since the managed cleanup also disables
runtime PM,drop the remove callback.

Fixes: c6a97c42e399 ("hwrng: stm32 - add support for STM32 HW RNG")
Cc: stable@vger.kernel.org
Signed-off-by: Can Peng <pengcan@kylinos.cn>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c
index 9a8c00586ab0..f5bfe54c01dc 100644
--- a/drivers/char/hw_random/stm32-rng.c
+++ b/drivers/char/hw_random/stm32-rng.c
@@ -368,11 +368,6 @@ static int stm32_rng_init(struct hwrng *rng)
 	return 0;
 }
 
-static void stm32_rng_remove(struct platform_device *ofdev)
-{
-	pm_runtime_disable(&ofdev->dev);
-}
-
 static int __maybe_unused stm32_rng_runtime_suspend(struct device *dev)
 {
 	struct stm32_rng_private *priv = dev_get_drvdata(dev);
@@ -590,7 +585,9 @@ static int stm32_rng_probe(struct platform_device *ofdev)
 
 	pm_runtime_set_autosuspend_delay(dev, 100);
 	pm_runtime_use_autosuspend(dev);
-	pm_runtime_enable(dev);
+	ret = devm_pm_runtime_enable(dev);
+	if (ret)
+		return ret;
 
 	return devm_hwrng_register(dev, &priv->rng);
 }
@@ -602,7 +599,6 @@ static struct platform_driver stm32_rng_driver = {
 		.of_match_table = stm32_rng_match,
 	},
 	.probe = stm32_rng_probe,
-	.remove = stm32_rng_remove,
 };
 
 module_platform_driver(stm32_rng_driver);

[PATCH 6.6.y] hwrng: stm32 - Fix runtime PM cleanup on registration failure

[Sasha Levin]

From: Can Peng <pengcan@kylinos.cn>

[ Upstream commit 1163a476a568f6c0f852d469c8e4c5a5f805adac ]

stm32_rng_probe() enables autosuspend and runtime PM before registering the
hwrng. If devm_hwrng_register() fails, probe returns with runtime PM left
enabled and autosuspend still selected.

The remove callback also only disables runtime PM and does not undo
pm_runtime_use_autosuspend().

Use devm_pm_runtime_enable() so runtime PM is unwound automatically on
probe failure and driver detach. Since the managed cleanup also disables
runtime PM,drop the remove callback.

Fixes: c6a97c42e399 ("hwrng: stm32 - add support for STM32 HW RNG")
Cc: stable@vger.kernel.org
Signed-off-by: Can Peng <pengcan@kylinos.cn>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
[ adapted to the older driver’s relocated int-returning remove callback and existing err variable. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/char/hw_random/stm32-rng.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c
index efb6a9f9a11b5..fcfb0c4cea236 100644
--- a/drivers/char/hw_random/stm32-rng.c
+++ b/drivers/char/hw_random/stm32-rng.c
@@ -159,18 +159,13 @@ static int stm32_rng_probe(struct platform_device *ofdev)
 
 	pm_runtime_set_autosuspend_delay(dev, 100);
 	pm_runtime_use_autosuspend(dev);
-	pm_runtime_enable(dev);
+	err = devm_pm_runtime_enable(dev);
+	if (err)
+		return err;
 
 	return devm_hwrng_register(dev, &priv->rng);
 }
 
-static int stm32_rng_remove(struct platform_device *ofdev)
-{
-	pm_runtime_disable(&ofdev->dev);
-
-	return 0;
-}
-
 #ifdef CONFIG_PM
 static int stm32_rng_runtime_suspend(struct device *dev)
 {
@@ -212,7 +207,6 @@ static struct platform_driver stm32_rng_driver = {
 		.of_match_table = stm32_rng_match,
 	},
 	.probe = stm32_rng_probe,
-	.remove = stm32_rng_remove,
 };
 
 module_platform_driver(stm32_rng_driver);
-- 
2.53.0