Re: [PATCH 2/2] arm64: dts: qcom: qcm6490-idp: add display and panel

[Ritesh Kumar]

On 1/23/2024 11:34 PM, Konrad Dybcio wrote:
> On 1/23/24 16:12, Dmitry Baryshkov wrote:
> > On Tue, 23 Jan 2024 at 15:43, Ritesh Kumar <quic_riteshk@xxxxxxxxxxx> 
> > wrote:
> > > On 1/16/2024 6:27 PM, Dmitry Baryshkov wrote:
> > >
> > > > On Tue, 16 Jan 2024 at 14:06, Konrad Dybcio 
> > > > <konrad.dybcio@xxxxxxxxxx> wrote:
> > > > > On 1/16/24 10:49, Ritesh Kumar wrote:
> > > > > > Enable Display Subsystem with Novatek NT36672E Panel
> > > > > > on qcm6490 idp platform.
> > > > > >
> > > > > > Signed-off-by: Ritesh Kumar <quic_riteshk@xxxxxxxxxxx>
> > > > > > ---
> > > > > >     arch/arm64/boot/dts/qcom/qcm6490-idp.dts | 100 
> > > > > > +++++++++++++++++++++++
> > > > > >     1 file changed, 100 insertions(+)
> > > > > >
> > > > > > diff --git a/arch/arm64/boot/dts/qcom/qcm6490-idp.dts 
> > > > > > b/arch/arm64/boot/dts/qcom/qcm6490-idp.dts
> > > > > > index 2a6e4907c5ee..efa5252130a1 100644
> > > > > > --- a/arch/arm64/boot/dts/qcom/qcm6490-idp.dts
> > > > > > +++ b/arch/arm64/boot/dts/qcom/qcm6490-idp.dts
> > > > > > @@ -9,6 +9,7 @@
> > > > > >     #define PM7250B_SID 8
> > > > > >     #define PM7250B_SID1 9
> > > > > >
> > > > > > +#include <dt-bindings/pinctrl/qcom,pmic-gpio.h>
> > > > > >     #include <dt-bindings/regulator/qcom,rpmh-regulator.h>
> > > > > >     #include "sc7280.dtsi"
> > > > > >     #include "pm7250b.dtsi"
> > > > > > @@ -38,6 +39,25 @@
> > > > > >                 stdout-path = "serial0:115200n8";
> > > > > >         };
> > > > > >
> > > > > > +     lcd_disp_bias: lcd-disp-bias-regulator {
> > > > > > +             compatible = "regulator-fixed";
> > > > > > +             regulator-name = "lcd_disp_bias";
> > > > > > +             regulator-min-microvolt = <5500000>;
> > > > > > +             regulator-max-microvolt = <5500000>;
> > > > > > +             gpio = <&pm7250b_gpios 2 GPIO_ACTIVE_HIGH>;
> > > > > > +             enable-active-high;
> > > > > > +             pinctrl-names = "default";
> > > > > > +             pinctrl-0 = <&lcd_disp_bias_en>;
> > > > > property-n
> > > > > property-names
> > > > >
> > > > > all throughout the patch
> > >
> > > Thanks, I will update in the new version.
> > >
> > > > > > +&gpu {
> > > > > > +     status = "disabled";
> > > > > > +};
> > > > > Hm.. generally we disable the GPU in the SoC DT, but that doesn't
> > > > > seem to have happened here..
> > > > >
> > > > > Thinking about it more, is disabling it here necessary? Does it
> > > > > not fail gracefully?
> > > > Missed this.
> > > >
> > > > I'd say, I don't see a reason to disable it at all. The GPU should be
> > > > working on sc7280 / qcm4290.
> > >
> > > With GPU device node enabled, adreno_bind failure is seen as the
> > > "speed_bin" was not populated on QCM6490 target which leads to display
> > > bind failure.
> >
> > Excuse me please. The GPU node for sc7280 already has speed_bin, which
> > points to qfprom + 0x1e9, bits 5 to 9.
> >
> > Do you mean that qcm6490 uses different speed bin location? Or
> > different values for the speed bins?
> >
> > > Spoke with GPU team and on QCM6490 board, only CPU rendering is
> > > supported for now and there is no plan to enable GPU rendering in near
> > > future.
> >
> > This sounds like having the feature disabled for no particular reason.
> > Both the kernel and Mesa have supported the Adreno 635 for quite a
> > while.
>
> 643 [1], [2]
>
> > > In this regard, what do you suggest
> > >
> > > 1) Disable GPU in QCM6490 DT (as per the current patch)
> > > 2) Disable GPU in the SoC DT, but enable it in other platform DTs. 
> > > (This
> > > will prompt change in all the dt's and we don't have all the devices to
> > > test)
> >
> > The second option definitely follows what is present on other platforms.
> >
> > > Please let me know your views on it.
> >
> > Please enable the GPU instead.
>
> +1
>
> Konrad
>
> [1] 
> https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25408/diffs?commit_id=b1e851d66c3a3e53f1a464023f675f3f6cbd3503
> [2] 
> https://patches.linaro.org/project/linux-arm-msm/cover/20230926-topic-a643-v1-0-7af6937ac0a3@xxxxxxxxxx/

Thanks for the help. After applying missing patches from series 
https://patches.linaro.org/project/linux-arm-msm/cover/20230926-topic-a643-v1-0-7af6937ac0a3@xxxxxxxxxx/
in my local build, GPU is working fine. GPU disablement change is not 
needed. I will send new version of patch removing GPU part and 
addressing other review comments.

Thanks,
Ritesh