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

[Guangshuo Li]

panfrost_probe() calls pm_runtime_use_autosuspend(), but neither the
probe error path nor panfrost_remove() calls the matching
pm_runtime_dont_use_autosuspend() during teardown.

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.

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 both the
probe failure and device removal paths.

This issue was found by manual code inspection.

Fixes: f3ba91228e8e ("drm/panfrost: Add initial panfrost driver")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
---
 drivers/gpu/drm/panfrost/panfrost_drv.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index 784e36d72c2b..007dcba62e62 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -1011,6 +1011,7 @@ static int panfrost_probe(struct platform_device *pdev)
 err_out2:
 	drm_dev_unregister(&pfdev->base);
 err_out1:
+	pm_runtime_dont_use_autosuspend(pfdev->base.dev);
 	pm_runtime_disable(pfdev->base.dev);
 	panfrost_device_fini(pfdev);
 	pm_runtime_set_suspended(pfdev->base.dev);
@@ -1025,6 +1026,7 @@ static void panfrost_remove(struct platform_device *pdev)
 	drm_dev_unregister(&pfdev->base);
 	panfrost_gem_shrinker_cleanup(&pfdev->base);
 
+	pm_runtime_dont_use_autosuspend(pfdev->base.dev);
 	pm_runtime_get_sync(pfdev->base.dev);
 	pm_runtime_disable(pfdev->base.dev);
 	panfrost_device_fini(pfdev);
-- 
2.43.0