Re: [PATCH v4 0/3] Add CAMSS support for SM6350

[Vladimir Zapolskiy]

Hi Luca.

On 4/3/26 11:09, Luca Weiss wrote:
> Hi Vladimir,
>
> On Tue Mar 31, 2026 at 12:49 AM CEST, Vladimir Zapolskiy wrote:
> > Hi Luca,
> >
> > On 2/16/26 10:54, Luca Weiss wrote:
> > > Add bindings, driver and dts to support the Camera Subsystem on the
> > > SM6350 SoC.
> > >
> > > These patches were tested on a Fairphone 4 smartphone with WIP sensor
> > > drivers (Sony IMX576 and IMX582), the camera pipeline works properly as
> > > far as I can tell.
> > >
> > > Though when stopping the camera stream, the following clock warning
> > > appears in dmesg. But it does not interfere with any functionality,
> > > starting and stopping the stream works and debugcc is showing 426.4 MHz
> > > while the clock is on, and 'off' while it's off.
> > >
> > > Any suggestion how to fix this, is appreciated.
> >
> > I've looked at CAMCC recently, and I do notice that SM6350 CAMCC does not
> > set '.use_rpm = true' flag for whatever reason.
> >
> > If you find a free minute, can you test the change below?..
>
> Unfortunately that change does not resolve the "gcc_camera_axi_clk
> status stuck at 'on'" warning.
>
> fairphone-fp4:~$ cat /sys/bus/platform/drivers/sm6350-camcc/ad00000.clock-controller/power/runtime_status
> active
>
> fairphone-fp4:~$ cat /sys/bus/platform/drivers/sm6350-camcc/ad00000.clock-controller/power/runtime_status
> suspended

So it seems to be a technically deeper issue, once given insights by Imran
likely to be very relevant:
https://lore.kernel.org/linux-arm-msm/caa870e2-3795-40bc-9f0e-c93e313c8c6e@xxxxxxxxxxxxxxxx/

> > ----8<----
> > diff --git a/drivers/clk/qcom/camcc-sm6350.c b/drivers/clk/qcom/camcc-sm6350.c
> > index 7df12c1311c6..ba880e4edcaf 100644
> > --- a/drivers/clk/qcom/camcc-sm6350.c
> > +++ b/drivers/clk/qcom/camcc-sm6350.c
> > @@ -1880,6 +1880,7 @@ static const struct qcom_cc_desc camcc_sm6350_desc = {
> >    	.num_clks = ARRAY_SIZE(camcc_sm6350_clocks),
> >    	.gdscs = camcc_sm6350_gdscs,
> >    	.num_gdscs = ARRAY_SIZE(camcc_sm6350_gdscs),
> > +	.use_rpm = true,
> >    };
> >    
> >    static const struct of_device_id camcc_sm6350_match_table[] = {
> > ----8<----
> >
> > This change could be considered to be included in any case, I believe.
>
> I guess this change is now the way to enable pm_runtime, I had this
> series 3 years ago in February 2023:
> https://lore.kernel.org/linux-arm-msm/20230213-sm6350-camcc-runtime_pm-v3-0-d35e0d833cc4@xxxxxxxxxxxxx/
>
> But I never followed up due to me not understanding pm_runtime well and
> no direct need for it.
>
> But I guess reviving that with use_rpm = true, add power-domains &
> required-opps to dt-bindings and sm6350.dtsi should be a good idea?

It should be, if SM6350 CAMCC is known to belong to an on-SoC power domain,
then devm_pm_runtime_enable() will be called on .probe to embed the
controller driver into the runtime PM framework, see commit c0b6627369bc.
Power domain management of devices is handled inside the runtime PM.

--
Best wishes,
Vladimir