[PATCH] dmaengine: ste_dma40: fix autosuspend cleanup on probe failure

[Guangshuo Li]

d40_probe() calls pm_runtime_use_autosuspend(), but its error path does
not call 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 cleanup, this reference is not dropped and usage_count remains
unbalanced.

Add the missing pm_runtime_dont_use_autosuspend() call to the probe
failure path before disabling runtime PM.

This issue was found by manual code inspection.

Fixes: 8d318a50b3d7 ("DMAENGINE: Support for ST-Ericssons DMA40 block v3")
Cc: stable at vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244 at gmail.com>
---
 drivers/dma/ste_dma40.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 0d9ffa3e2663..e2ad50e0fec4 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -3654,6 +3654,7 @@ static int __init d40_probe(struct platform_device *pdev)
 		regulator_disable(base->lcpa_regulator);
 		regulator_put(base->lcpa_regulator);
 	}
+	pm_runtime_dont_use_autosuspend(base->dev);
 	pm_runtime_disable(base->dev);
 
  report_failure:
-- 
2.43.0