[PATCH 3/5] drm: msm: add support for A750 GPU

[Konrad Dybcio]

On 12.02.2024 15:45, Neil Armstrong wrote:
> On 12/02/2024 11:46, Konrad Dybcio wrote:
>> On 12.02.2024 11:37, Neil Armstrong wrote:
>>> Add support for the A750 GPU found on the SM8650 platform
>>>
>>> Unlike the the very close A740 GPU on the SM8550 SoC, the A750 GPU
>>> doesn't have an HWCFG block but a separate register set.
>>>
>>> The missing registers are added in the a6xx.xml.h file that would
>>> require a subsequent sync and the non-existent hwcfg is handled
>>> in a6xx_set_hwcg().
>>
>> These should also be submitted to mesa to make sure the next header sync
>> doesn't wipe them
> 
> Ack submitting them right now: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27576

Thanks

> 
>>
>> [...]
>>
>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
>>> @@ -958,10 +958,11 @@ static void a6xx_set_hwcg(struct msm_gpu *gpu, bool state)
>>>       struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
>>>       struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
>>>       const struct adreno_reglist *reg;
>>> +    bool skip_programming = !(adreno_gpu->info->hwcg || adreno_is_a7xx(adreno_gpu));
>>
>> is_a750?
> 
> OK right, I was thinking of the next gpu which will probably also miss an hwcfg
> 
>>
>>>       unsigned int i;
>>>       u32 val, clock_cntl_on, cgc_mode;
>>>   -    if (!adreno_gpu->info->hwcg)
>>> +    if (skip_programming)
>>>           return;
>>>         if (adreno_is_a630(adreno_gpu))
>>> @@ -982,6 +983,25 @@ static void a6xx_set_hwcg(struct msm_gpu *gpu, bool state)
>>>                 state ? 0x5555 : 0);
>>>       }
>>>   +    if (!adreno_gpu->info->hwcg) {
>>
>> I don't think this block of code is reachable now, no?
> 
> It is because we didn't skip when adreno_is_a7xx(adreno_gpu)

Ahh I misread the brackets within the assignment

> 
>>
>> Maybe remove the skip_programming and if_a750 here?
> This would require:
>>> -    if (!adreno_gpu->info->hwcg || )
>>> +    if (!(adreno_gpu->info->hwcg || adreno_is_a750(adreno_gpu)))
> 
> and:
> 
>>> +    if (adreno_is_a750(adreno_gpu)) {
> 
> But if the next gpu also doesn't have an hwcfg, we will need to use
> the current design...
> 
> I just tried with:
> ====================><===============================
> @@ -961,7 +961,7 @@ static void a6xx_set_hwcg(struct msm_gpu *gpu, bool state)
>         unsigned int i;
>         u32 val, clock_cntl_on, cgc_mode;
> 
> -       if (!adreno_gpu->info->hwcg)
> +       if (!(adreno_gpu->info->hwcg || adreno_is_a750(adreno_gpu)))
>                 return;
> 
>         if (adreno_is_a630(adreno_gpu))
> @@ -982,6 +982,25 @@ static void a6xx_set_hwcg(struct msm_gpu *gpu, bool state)
>                           state ? 0x5555 : 0);
>         }
> 
> +       if (adreno_is_a750(adreno_gpu)) {
> +               gpu_write(gpu, REG_A7XX_RBBM_CLOCK_CNTL_GLOBAL, 1);
> +               gpu_write(gpu, REG_A7XX_RBBM_CGC_GLOBAL_LOAD_CMD, state ? 1 : 0);
> +
> +               if (state) {
> +                       gpu_write(gpu, REG_A7XX_RBBM_CGC_P2S_TRIG_CMD, 1);
> +
> +                       if (gpu_poll_timeout(gpu, REG_A7XX_RBBM_CGC_P2S_STATUS, val,
> +                                            val & A7XX_RBBM_CGC_P2S_STATUS_TXDONE, 1, 10)) {
> +                               dev_err(&gpu->pdev->dev, "RBBM_CGC_P2S_STATUS TXDONE Poll failed\n");
> +                               return;
> +                       }
> +
> +                       gpu_write(gpu, REG_A7XX_RBBM_CLOCK_CNTL_GLOBAL, 0);
> +               }
> +
> +               return;
> +       }
> +
>         val = gpu_read(gpu, REG_A6XX_RBBM_CLOCK_CNTL);
> 
>         /* Don't re-program the registers if they are already correct */
> ====================><===============================
> 
> And it works fine, does it work it for you ?

Let's keep it as-is in the original submission, as I've mentioned, I had
misread the code

Konrad

> 
>>
>>> +        gpu_write(gpu, REG_A7XX_RBBM_CLOCK_CNTL_GLOBAL, 1);
>>> +        gpu_write(gpu, REG_A7XX_RBBM_CGC_GLOBAL_LOAD_CMD, state ? 1 : 0);
>>> +
>>> +        if (state) {
>>> +            gpu_write(gpu, REG_A7XX_RBBM_CGC_P2S_TRIG_CMD, 1);
>>> +
>>> +            if (gpu_poll_timeout(gpu, REG_A7XX_RBBM_CGC_P2S_STATUS, val,
>>> +                         val & BIT(0), 1, 10)) {
>>
>> We should define that bit name (the err suggests it's
>> REG_A7XX_RBBM_GCC_P2S_STATUS_TXDONE or so)
>>
>> [...]
>>
>>> +static inline int adreno_is_a750(struct adreno_gpu *gpu)
>>> +{
>>> +    return gpu->info->chip_ids[0] == 0x43051401;
>>> +}
>>> +
>>>   /* Placeholder to make future diffs smaller */
>>
>> Please also remove this comment now that it's invalid
> 
> Ack
> 
>>
>> Konrad
> 
> Thanks,
> Neil
>