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

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

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.

Neil

> 
> Konrad