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

[Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>]

On Fri, 6 Sept 2024 at 06:51, Jinjie Ruan <ruanjinjie@xxxxxxxxxx> wrote:
>
>
>
> 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.

You can use the devm_pm_runtime_enable() here and land the rest of the
cleanups afterwards.

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



-- 
With best wishes
Dmitry