Re: [PATCH RFC RFT] drm/msm: adreno: attach the GMU device to a driver

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 10/23/25 10:27 AM, Neil Armstrong wrote:
> On 10/22/25 19:09, Konrad Dybcio wrote:
>> On 10/22/25 2:44 PM, Neil Armstrong wrote:
>>> Due to the sync_state is enabled by default in pmdomain & CCF since v6.17,
>>> the GCC and GPUCC sync_state would stay pending, leaving the resources in
>>> full performance:
>>> gcc-x1e80100 100000.clock-controller: sync_state() pending due to 3d6a000.gmu
>>> gpucc-x1e80100 3d90000.clock-controller: sync_state() pending due to 3d6a000.gmu
>>
>> Does this *actually* cause any harm, by the way?
> 
> ?
> 
>>
>> For example on x1e, GMU refers to 2 GPU_CC GDSCs, GPU_CC refers
>> to a pair of GCC clocks and GCC refers to VDD_CX
>>
>> and I see these prints, yet:
>>
>> /sys/kernel/debug/pm_genpd/gpu_cx_gdsc/current_state:off-0
>> /sys/kernel/debug/pm_genpd/gpu_gx_gdsc/current_state:off-0
>>
>> /sys/kernel/debug/pm_genpd/cx/current_state:on
>> /sys/kernel/debug/pm_genpd/cx/perf_state:256 # because of USB3 votes
>>
>> I'm not super sure where that sync_state comes from either (maybe
>> dev_set_drv_sync_state in pmdomain/core?)
> 
> The way we handle the GMU so far is wrong, it abuses the driver model.
> 
> And this is a symptom, whatever the impact it has, it needs to be fixed
> in a proper way.
> 
> The sync_state is retained because the gmu device is never probed but
> has some clocks and power domains attached to it, which is clearly wrong.

Yes I agree, however I'm only debating the commit message claims of
'leaving the resources in full performance', which doesn't seem to be
true

Konrad