[PATCH] crypto: sl3516: fix autosuspend cleanup during teardown

[Guangshuo Li]

sl3516_ce_pm_init() calls pm_runtime_use_autosuspend(), but the
autosuspend setting is not undone if pm_runtime_set_suspended() fails
or when runtime PM is later torn down by sl3516_ce_pm_exit().

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 cleanup, this reference is not dropped and usage_count remains
unbalanced.

Undo the autosuspend setting when pm_runtime_set_suspended() fails and
in sl3516_ce_pm_exit() before disabling runtime PM.

This issue was found by manual code inspection.

Fixes: 46c5338db7bd ("crypto: sl3516 - Add sl3516 crypto engine")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
---
 drivers/crypto/gemini/sl3516-ce-core.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/gemini/sl3516-ce-core.c b/drivers/crypto/gemini/sl3516-ce-core.c
index f7e0e3fea15c..f09a7f3445e4 100644
--- a/drivers/crypto/gemini/sl3516-ce-core.c
+++ b/drivers/crypto/gemini/sl3516-ce-core.c
@@ -381,14 +381,17 @@ static int sl3516_ce_pm_init(struct sl3516_ce_dev *ce)
 	pm_runtime_set_autosuspend_delay(ce->dev, 2000);
 
 	err = pm_runtime_set_suspended(ce->dev);
-	if (err)
+	if (err) {
+		pm_runtime_dont_use_autosuspend(ce->dev);
 		return err;
+	}
 	pm_runtime_enable(ce->dev);
 	return err;
 }
 
 static void sl3516_ce_pm_exit(struct sl3516_ce_dev *ce)
 {
+	pm_runtime_dont_use_autosuspend(ce->dev);
 	pm_runtime_disable(ce->dev);
 }
 
-- 
2.43.0