# Re: \[PATCH\] drm/stm: repair runtime power management

- From: Marek Vasut \<marex@denx.de\>
- Date: 2020-07-02 10:54:59 
- List: linux-arm-kernel
- Page: https://ratatoskr.run/linux-arm-kernel/2020/07/8796015
- Thread: https://ratatoskr.run/dri-devel/2020/02/8791670/t.md

```text
On 7/2/20 12:07 PM, Philippe CORNU wrote:

Hi,

[...]

>>>> Thank for your patch. Pm_runtime_put_sync is also done into function ltdc_crtc_mode_fixup.
>>>> To avoid several call of Pm_runtime_put_sync, it could be better to check pm_runtime activity:
>>>>
>>>> +	int ret;
>>>>    
>>>>    	DRM_DEBUG_DRIVER("\n");
>>>>    
>>>> +	if (!pm_runtime_active(ddev->dev)) {
>>>> +		ret = pm_runtime_get_sync(ddev->dev);
>>>> +		if (ret) {
>>>> +			DRM_ERROR("Failed to enable crtc, cannot get sync\n");
>>>> +			return;
>>>> +		}
>>>> +	}
>>>> +
>>>
>>> Where should this go ? And wouldn't that only hide nastier PM imbalance
>>> issues ?
>> Hi Marek,
>> I tested the patch &  it generate an error when I try wake up / sleep
>> the board STM32MP1 DK2 with weston application.
>> It need an additional patch
>> drm-stm-ltdc-remove-call-of-pm-runtime-functions.
>>
>> Thanks for the patch.
>>
>> Tested-by: Yannick Fertre <redacted>
>>
> 
> Hi Marek,
> before merging the 2 patches, I would like to be sure that Yannick's 
> patch does not "break" your use case (Qt I think)?
> May I ask you please to give it a try?
> Note: If you think there is no need to do extra checks, simply tell me 
> of course
It's fine, thanks !

-- 
Best regards,
Marek Vasut

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
```