On 27/11/2020 09:44, Qinglang Miao wrote:
pm_runtime_get_sync will increment pm usage counter even it
failed. Forgetting to putting operation will result in a
reference leak here.
A new function pm_runtime_resume_and_get is introduced in
[0] to keep usage counter balanced. So We fix the reference
leak by replacing it with new funtion.
[0] dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
Fixes: f3ba91228e8e ("drm/panfrost: Add initial panfrost driver")
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Qinglang Miao <miaoqinglang@xxxxxxxxxx>
---
drivers/gpu/drm/panfrost/panfrost_job.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
index 30e7b7196..04cf3bb67 100644
--- a/drivers/gpu/drm/panfrost/panfrost_job.c
+++ b/drivers/gpu/drm/panfrost/panfrost_job.c
@@ -147,7 +147,7 @@ static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
panfrost_devfreq_record_busy(&pfdev->pfdevfreq);
- ret = pm_runtime_get_sync(pfdev->dev);
+ ret = pm_runtime_resume_and_get(pfdev->dev);
Sorry, but in this case this change isn't correct.
panfrost_job_hw_submit() is expected to be unbalanced (the PM reference
count is expected to be incremented on return).
In the case where pm_runtime_get_sync() fails, the job will eventually
timeout, and there's a corresponding pm_runtime_put_noidle() in
panfrost_reset().
Potentially this could be handled better (e.g. without waiting for the
timeout to occur), but equally this isn't something we expect to happen
in normal operation).
Steve
if (ret < 0)
return;
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