On Tue, 30 May 2023 at 02:47, Dmitry Baryshkov
<dmitry.baryshkov@xxxxxxxxxx> wrote:
>
> On 11/05/2023 11:15, Manivannan Sadhasivam wrote:
> > On Tue, May 09, 2023 at 02:20:07PM +0300, Dmitry Baryshkov wrote:
> >> On Tue, 9 May 2023 at 08:50, Manivannan Sadhasivam
> >> <manivannan.sadhasivam@xxxxxxxxxx> wrote:
> >>>
> >>> On Sun, May 07, 2023 at 08:53:35PM +0300, Dmitry Baryshkov wrote:
> >>>> Using PWRSTS_RET on msm8974's MDSS_GDSC causes display to stop working.
> >>>> The gdsc doesn't fully come out of retention mode. Change it's pwrsts
> >>>> flags to PWRSTS_OFF_ON.
> >>>>
> >>>
> >>> What does "stop working" implies? Does it work during boot and randomly stopped
> >>> working or it stopped working after resume from suspend?
> >>
> >> It stops working during the boot. I observed the MDP not starting up
> >> properly. Mea culpa, I did not look deep enough into the details, just
> >> stomped upon this change which fixes the problem for me.
> >>
> >
> > IIUC, GDSC will be transitioned to retention mode only if the parent domain goes
> > to low power mode. So if the MDSS GDSC goes to retention mode during boot, then
> > it suggests that the parent domain is not voted properly. Unless I misunderstood
> > something...
>
> Not sure, what is the parent domain here. Note, it is a pretty old
> implementation.
Colleagues, any further feedback on this? I'd like to note that all
other platforms use PWRSTS_OFF_ON for the MDSS_GDSC,
I do not think that msm8974 is particularly different here.
>
> >
> > Or is the GDSC behavior changes between RPM and RPMh?
> >
> > - Mani
> >
> >>>
> >>> Even though reverting to non-retention mode works, I think the issue might be
> >>> somewhere else. Like the vote might be missing to get the GDSC out of retention
> >>> mode.
> >>
> >> I don't think there is a vote missing. The driver votes on MDSS_GDSC
> >> before enabling access to any of the registers from the MDSS region.
> >>
> >>>
> >>> - Mani
> >>>
> >>>> Fixes: d399723950c4 ("clk: qcom: gdsc: Fix the handling of PWRSTS_RET support")
> >>>> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> >>>> ---
> >>>> drivers/clk/qcom/mmcc-msm8974.c | 2 +-
> >>>> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>>>
> >>>> diff --git a/drivers/clk/qcom/mmcc-msm8974.c b/drivers/clk/qcom/mmcc-msm8974.c
> >>>> index aa29c79fcd55..277ef0065aae 100644
> >>>> --- a/drivers/clk/qcom/mmcc-msm8974.c
> >>>> +++ b/drivers/clk/qcom/mmcc-msm8974.c
> >>>> @@ -2401,7 +2401,7 @@ static struct gdsc mdss_gdsc = {
> >>>> .pd = {
> >>>> .name = "mdss",
> >>>> },
> >>>> - .pwrsts = PWRSTS_RET_ON,
> >>>> + .pwrsts = PWRSTS_OFF_ON,
> >>>> };
> >>>>
> >>>> static struct gdsc camss_jpeg_gdsc = {
> >>>> --
> >>>> 2.39.2
> >>>>
> >>>
> >>> --
> >>> மணிவண்ணன் சதாசிவம்
> >>
> >>
> >>
> >> --
> >> With best wishes
> >> Dmitry
> >
>
> --
> With best wishes
> Dmitry
>
--
With best wishes
Dmitry
