[PATCH 2/3] media: platform: mtk-mdp3: fix PM reference leak in mdp_comp_clock_on()

[Hans Verkuil]

It's in a pull request, waiting to be merged.

Regards,

	Hans

On 23/09/2022 08:25, Sun Ke wrote:
> ping...
> 
> 在 2022/9/2 16:58, Sun Ke 写道:
>> mdp_comp_clock_on will increase runtime PM usage counter,
>> and mdp_comp_clock_off will decrease the runtime PM usage counter.
>> so, if mdp_comp_clock_on failed after increment runtime PM usage
>> counter, it should decrease it before return a error code.
>>
>> pm_runtime_get_sync will increment pm usage counter even it failed.
>> Forgetting to putting operation will result in reference leak here.
>> Fix it by replacing it with pm_runtime_resume_and_get to keep usage
>> counter balanced.
>>
>> And if failed to enable clk, add pm_runtime_put() to decrease the
>> runtime PM usage counter.
>>
>> Fixes: 61890ccaefaf ("media: platform: mtk-mdp3: add MediaTek MDP3 driver")
>> Signed-off-by: Sun Ke <sunke32 at huawei.com>
>> ---
>>   drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
>> index 9a6ba5851ccb..d3eaf8884412 100644
>> --- a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
>> +++ b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
>> @@ -682,7 +682,7 @@ int mdp_comp_clock_on(struct device *dev, struct mdp_comp *comp)
>>       int i, ret;
>>         if (comp->comp_dev) {
>> -        ret = pm_runtime_get_sync(comp->comp_dev);
>> +        ret = pm_runtime_resume_and_get(comp->comp_dev);
>>           if (ret < 0) {
>>               dev_err(dev,
>>                   "Failed to get power, err %d. type:%d id:%d\n",
>> @@ -699,6 +699,7 @@ int mdp_comp_clock_on(struct device *dev, struct mdp_comp *comp)
>>               dev_err(dev,
>>                   "Failed to enable clk %d. type:%d id:%d\n",
>>                   i, comp->type, comp->id);
>> +            pm_runtime_put(comp->comp_dev);
>>               return ret;
>>           }
>>       }
>>