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

[Jinjie Ruan <ruanjinjie@huawei.com>]

On 2024/9/6 11:52, Dmitry Baryshkov wrote:
> On Fri, 6 Sept 2024 at 06:51, Jinjie Ruan <ruanjinjie@huawei.com> wrote:
>>
>>
>>
>> On 2024/9/6 11:43, Dmitry Baryshkov wrote:
>>> On Fri, 6 Sept 2024 at 06:41, Jinjie Ruan <ruanjinjie@huawei.com> wrote:
>>>>
>>>>
>>>>
>>>> On 2024/9/6 11:36, Dmitry Baryshkov wrote:
>>>>> On Fri, 6 Sept 2024 at 06:31, Jinjie Ruan <ruanjinjie@huawei.com> 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@mail.gmail.com/
>>>>>
>>>>> 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.
> 
> You can use the devm_pm_runtime_enable() here and land the rest of the
> cleanups afterwards.

But Doug suggest that the bug fix patch should not contain "-next", but
the cleanup patch is "-next", which let me split them 🤣

> 
>>
>>>
>>>>
>>>>
>>>>>
>>>>>>
>>>>>>>
>>>>>>>> ---
>>>>>>>>  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
>>>>>>>>
>>>>>>>
>>>>>
>>>>>
>>>>>
>>>
>>>
>>>
> 
> 
>