etnaviv_gpu_platform_probe() calls pm_runtime_use_autosuspend() and
enables runtime PM before registering the component. If component_add()
fails, the probe path returns without undoing the autosuspend setting
or disabling runtime PM. The remove path also disables runtime PM
without calling the matching pm_runtime_dont_use_autosuspend().
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.
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().
Undo the autosuspend setting on both probe failure and device removal,
and disable runtime PM on the component registration failure path.
This issue was found by manual code inspection.
Fixes: a8c21a5451d8 ("drm/etnaviv: add initial etnaviv DRM driver")
Cc: [email protected]
Signed-off-by: Guangshuo Li <[email protected]>
---
drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
index c314b3cb5e70..7acf2ed651f3 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
@@ -1964,6 +1964,8 @@ static int etnaviv_gpu_platform_probe(struct
platform_device *pdev)
err = component_add(dev, &gpu_ops);
if (err < 0) {
dev_err(dev, "failed to register component: %d\n", err);
+ pm_runtime_dont_use_autosuspend(dev);
+ pm_runtime_disable(dev);
return err;
}
@@ -1975,6 +1977,7 @@ static void etnaviv_gpu_platform_remove(struct
platform_device *pdev)
struct etnaviv_gpu *gpu = dev_get_drvdata(&pdev->dev);
component_del(&pdev->dev, &gpu_ops);
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
pm_runtime_disable(&pdev->dev);
mutex_destroy(&gpu->lock);
--
2.43.0
