[PATCH] drm/lima: fix autosuspend cleanup during teardown

[Guangshuo Li]

lima_pdev_probe() calls pm_runtime_use_autosuspend(), but its failure
path does not call the matching pm_runtime_dont_use_autosuspend()
before disabling runtime PM. The remove path has the same issue.

In particular, lima_pdev_remove() explicitly sets the autosuspend
delay to -1 while autosuspend is still enabled. A negative autosuspend
delay can increase usage_count to prevent runtime suspend. Without
calling pm_runtime_dont_use_autosuspend(), this reference is not
dropped before runtime PM is disabled, leaving usage_count unbalanced.

The documentation for pm_runtime_use_autosuspend() also notes that it
is important to undo it with pm_runtime_dont_use_autosuspend() at
driver exit time, unless runtime PM was initially enabled with
devm_pm_runtime_enable().

Add the missing pm_runtime_dont_use_autosuspend() calls to the probe
failure and remove paths.

This issue was found by manual code inspection.

Fixes: 50de2e9ebbc0 ("drm/lima: enable runtime pm")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
---
 drivers/gpu/drm/lima/lima_drv.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/lima/lima_drv.c b/drivers/gpu/drm/lima/lima_drv.c
index 9a0eb1092ad3..9bd44c191e6c 100644
--- a/drivers/gpu/drm/lima/lima_drv.c
+++ b/drivers/gpu/drm/lima/lima_drv.c
@@ -434,6 +434,7 @@ static int lima_pdev_probe(struct platform_device *pdev)
 	return 0;
 
 err_out3:
+	pm_runtime_dont_use_autosuspend(ldev->dev);
 	pm_runtime_disable(ldev->dev);
 	lima_devfreq_fini(ldev);
 err_out2:
@@ -456,6 +457,7 @@ static void lima_pdev_remove(struct platform_device *pdev)
 
 	/* stop autosuspend to make sure device is in active state */
 	pm_runtime_set_autosuspend_delay(ldev->dev, -1);
+	pm_runtime_dont_use_autosuspend(ldev->dev);
 	pm_runtime_disable(ldev->dev);
 
 	lima_devfreq_fini(ldev);
-- 
2.43.0