Re: [PATCH RFC 6/8] drm/msm: adreno: enable GMU bandwidth for A740 and A750

[Neil Armstrong <neil.armstrong@linaro.org>]

On 15/11/2024 15:39, Dmitry Baryshkov wrote:
> On Fri, Nov 15, 2024 at 10:20:01AM +0100, Neil Armstrong wrote:
>> On 15/11/2024 08:33, Dmitry Baryshkov wrote:
>>> On Wed, Nov 13, 2024 at 04:48:32PM +0100, Neil Armstrong wrote:
>>>> Now all the DDR bandwidth voting via the GPU Management Unit (GMU)
>>>> is in place, let's declare the Bus Control Modules (BCMs) and
>>>
>>> s/let's //g
>>>
>>>> it's parameters in the GPU info struct and add the GMU_BW_VOTE
>>>> quirk to enable it.
>>>
>>> Can we define a function that checks for info.bcm[0].name isntead of
>>> adding a quirk?
>>
>> Probably, I'll need ideas to how design this better, perhaps a simple
>> capability bitfield in a6xx_info ?
> 
> I'm not sure if I follow the question. I think it's better to check for
> the presens of the data rather than having a separate 'cap' bit in
> addition to that data.

I don't fully agree here, I just follow the other features (CACHED_COHERENT/APRIV/...)
nothing fancy.
I'll introduce a features bitfield, so we don't mix them with quirks

> 
>> There's other feature that are lacking, like ACD or BCL which are not supported
>> on all a6xx/a7xx gpus.
> 
> Akhil is currently working on ACD, as you have seen from the patches.

Yep I've tested and reviewed the patches

> 
>>
>>>
>>>>
>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>> ---
>>>>    drivers/gpu/drm/msm/adreno/a6xx_catalog.c | 26 ++++++++++++++++++++++++--
>>>>    1 file changed, 24 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
>>>> index 0c560e84ad5a53bb4e8a49ba4e153ce9cf33f7ae..014a24256b832d8e03fe06a6516b5348a5c0474a 100644
>>>> --- a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
>>>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
>>>> @@ -1379,7 +1379,8 @@ static const struct adreno_info a7xx_gpus[] = {
>>>>    		.inactive_period = DRM_MSM_INACTIVE_PERIOD,
>>>>    		.quirks = ADRENO_QUIRK_HAS_CACHED_COHERENT |
>>>>    			  ADRENO_QUIRK_HAS_HW_APRIV |
>>>> -			  ADRENO_QUIRK_PREEMPTION,
>>>> +			  ADRENO_QUIRK_PREEMPTION |
>>>> +			  ADRENO_QUIRK_GMU_BW_VOTE,
>>>>    		.init = a6xx_gpu_init,
>>>>    		.zapfw = "a740_zap.mdt",
>>>>    		.a6xx = &(const struct a6xx_info) {
>>>> @@ -1388,6 +1389,16 @@ static const struct adreno_info a7xx_gpus[] = {
>>>>    			.pwrup_reglist = &a7xx_pwrup_reglist,
>>>>    			.gmu_chipid = 0x7020100,
>>>>    			.gmu_cgc_mode = 0x00020202,
>>>> +			.bcm = {
>>>> +				[0] = { .name = "SH0", .buswidth = 16 },
>>>> +				[1] = { .name = "MC0", .buswidth = 4 },
>>>> +				[2] = {
>>>> +					.name = "ACV",
>>>> +					.fixed = true,
>>>> +					.perfmode = BIT(3),
>>>> +					.perfmode_bw = 16500000,
>>>
>>> Is it a platform property or GPU / GMU property? Can expect that there
>>> might be several SoCs having the same GPU, but different perfmode_bw
>>> entry?
>>
>> I presume this is SoC specific ? But today the XXX_build_bw_table() are
>> already SoC specific, so where should this go ?
> 
> XXX_build_bw_table() are GPU-specific. There are cases of several SoCs
> sharing the same GPU on them.

So it's gpu-specific

> 
>> Downstream specifies this in the adreno-gpulist.h, which is the equivalent
>> here.
>