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

[Ritesh Kumar <quic_riteshk@quicinc.com>]

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@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/

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@linaro.org/
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