[PATCH] crypto: stm32/hash: fix autosuspend cleanup during teardown

[PATCH] crypto: stm32/hash: fix autosuspend cleanup during teardown

[Guangshuo Li]

stm32_hash_probe() calls pm_runtime_use_autosuspend(), but neither the
probe failure path nor stm32_hash_remove() calls the matching
pm_runtime_dont_use_autosuspend() before disabling runtime PM.

If the autosuspend delay is set to a negative value while autosuspend
is enabled, the runtime PM core increments usage_count to prevent
runtime suspend. Without calling pm_runtime_dont_use_autosuspend()
during teardown, this reference is not dropped and usage_count remains
unbalanced.

Add the missing pm_runtime_dont_use_autosuspend() calls to both the
probe failure and remove paths before disabling runtime PM.

This issue was found by manual code inspection.

Fixes: 8b4d566de6a5 ("crypto: stm32/hash - Add power management support")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 drivers/crypto/stm32/stm32-hash.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/crypto/stm32/stm32-hash.c b/drivers/crypto/stm32/stm32-hash.c
index dada5951082c..12fa1a8f67eb 100644
--- a/drivers/crypto/stm32/stm32-hash.c
+++ b/drivers/crypto/stm32/stm32-hash.c
@@ -2456,6 +2456,7 @@ static int stm32_hash_probe(struct platform_device *pdev)
 	if (hdev->dma_lch)
 		dma_release_channel(hdev->dma_lch);
 err_reset:
+	pm_runtime_dont_use_autosuspend(dev);
 	pm_runtime_disable(dev);
 	pm_runtime_put_noidle(dev);
 
@@ -2482,6 +2483,7 @@ static void stm32_hash_remove(struct platform_device *pdev)
 	if (hdev->dma_lch)
 		dma_release_channel(hdev->dma_lch);
 
+	pm_runtime_dont_use_autosuspend(hdev->dev);
 	pm_runtime_disable(hdev->dev);
 	pm_runtime_put_noidle(hdev->dev);
 
-- 
2.43.0

Re: [PATCH] crypto: stm32/hash: fix autosuspend cleanup during teardown

[Maxime MERE]

On 8/8/26 11:41, Guangshuo Li wrote:
> stm32_hash_probe() calls pm_runtime_use_autosuspend(), but neither the
> probe failure path nor stm32_hash_remove() calls the matching
> pm_runtime_dont_use_autosuspend() before disabling runtime PM.
> 
> If the autosuspend delay is set to a negative value while autosuspend
> is enabled, the runtime PM core increments usage_count to prevent
> runtime suspend. Without calling pm_runtime_dont_use_autosuspend()
> during teardown, this reference is not dropped and usage_count remains
> unbalanced.
> 
> Add the missing pm_runtime_dont_use_autosuspend() calls to both the
> probe failure and remove paths before disabling runtime PM.
> 
> This issue was found by manual code inspection.
> 
> Fixes: 8b4d566de6a5 ("crypto: stm32/hash - Add power management support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Reviewed-by: Maxime Méré <maxime.mere@foss.st.com>

Cheers,

Maxime