Re: [PATCH v2 2/2] spi: spi-geni-qcom: Fix missing undo runtime PM changes at driver exit time

[Jinjie Ruan <ruanjinjie@xxxxxxxxxx>]

On 2024/9/6 11:43, Dmitry Baryshkov wrote:
> On Fri, 6 Sept 2024 at 06:41, Jinjie Ruan <ruanjinjie@xxxxxxxxxx> wrote:
>>
>>
>>
>> On 2024/9/6 11:36, Dmitry Baryshkov wrote:
>>> On Fri, 6 Sept 2024 at 06:31, Jinjie Ruan <ruanjinjie@xxxxxxxxxx> wrote:
>>>>
>>>>
>>>>
>>>> On 2024/9/6 11:15, Dmitry Baryshkov wrote:
>>>>> On Fri, Sep 06, 2024 at 11:13:45AM GMT, Jinjie Ruan wrote:
>>>>>> It's important to undo pm_runtime_use_autosuspend() with
>>>>>> pm_runtime_dont_use_autosuspend() at driver exit time unless driver
>>>>>> initially enabled pm_runtime with devm_pm_runtime_enable()
>>>>>> (which handles it for you).
>>>>>>
>>>>>> Hence, call pm_runtime_dont_use_autosuspend() at driver exit time
>>>>>> to fix it.
>>>>>>
>>>>>> Fixes: cfdab2cd85ec ("spi: spi-geni-qcom: Set an autosuspend delay of 250 ms")
>>>>>> ---
>>>>>> v2:
>>>>>> - Fix it directly instead of use devm_pm_runtime_enable().
>>>>>
>>>>> Why?
>>>>
>>>> The devm* sequence will have some problem, which will not consistent
>>>> with the former.
>>>>
>>>> Link:
>>>> https://lore.kernel.org/all/CAD=FV=VyDk-e2KNiuiBcACFAdrQmihOH6X6BSpGB+T1MsgsiKw@xxxxxxxxxxxxxx/
>>>
>>> That comment was for devm_request_irq(), not devm_pm_runtime_enable().
>>
>>
>> In the very least, ** parch #2 needs to come before this one and that
>> would help, but it won't fix everything **. Specifically in order to
>> keep the order proper you'll need to use devm_add_action_or_reset() to
>> "devm-ize" the freeing of the DMA channels.
> 
> This is patch #2. so I don't understand your comment. Moreover you
> don't have to use devm for each and every possible item. However I
> think it makes sense for pm_runtime in this case.

You are right, only use devm_pm_runtime_enable() here, there is no
change for the resource release sequence, but I have a cleanup patch
ready to replace all these with devm*, which depends on the 2 fix patch.

> 
>>
>>
>>>
>>>>
>>>>>
>>>>>> ---
>>>>>>  drivers/spi/spi-geni-qcom.c | 2 ++
>>>>>>  1 file changed, 2 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
>>>>>> index fc2819effe2d..38857edbc785 100644
>>>>>> --- a/drivers/spi/spi-geni-qcom.c
>>>>>> +++ b/drivers/spi/spi-geni-qcom.c
>>>>>> @@ -1158,6 +1158,7 @@ static int spi_geni_probe(struct platform_device *pdev)
>>>>>>  spi_geni_release_dma:
>>>>>>      spi_geni_release_dma_chan(mas);
>>>>>>  spi_geni_probe_runtime_disable:
>>>>>> +    pm_runtime_dont_use_autosuspend(dev);
>>>>>>      pm_runtime_disable(dev);
>>>>>>      return ret;
>>>>>>  }
>>>>>> @@ -1174,6 +1175,7 @@ static void spi_geni_remove(struct platform_device *pdev)
>>>>>>
>>>>>>      spi_geni_release_dma_chan(mas);
>>>>>>
>>>>>> +    pm_runtime_dont_use_autosuspend(&pdev->dev);
>>>>>>      pm_runtime_disable(&pdev->dev);
>>>>>>  }
>>>>>>
>>>>>> --
>>>>>> 2.34.1
>>>>>>
>>>>>
>>>
>>>
>>>
> 
> 
>