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

[Konrad Dybcio <konrad.dybcio@linaro.org>]

On 1/23/24 16:12, Dmitry Baryshkov wrote:
> On Tue, 23 Jan 2024 at 15:43, Ritesh Kumar <quic_riteshk@quicinc.com> wrote:
>>
>>
>> On 1/16/2024 6:27 PM, Dmitry Baryshkov wrote:
>>
>>> On Tue, 16 Jan 2024 at 14:06, Konrad Dybcio <konrad.dybcio@linaro.org> 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@quicinc.com>
>>>>> ---
>>>>>     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@linaro.org/