[PATCH] arm64: dts: imx95: Use GPU_CGC as core clock for GPU

[Marek Vasut]

On 12/30/25 3:53 AM, Rain Yang wrote:
> On Tue, Dec 30, 2025 at 02:53:38AM +0100, Marek Vasut wrote:
>> On 12/8/25 3:02 AM, Rain Yang wrote:
>>
>>>>> Okay, I’ll submit a patch later.
>>>>> The commit message should reflect that only CLK_GPU_CGC is enabled.
>>>>
>>>> The commit message , and this change , is unrelated to GPUAPB clock.
>>> The commit message is ambiguous. Could you clarify which parent clock
>>> you are referring to, and whether it can be enabled by CLK_GPU_CGC?
>>> If it was CLK_GPU, CLK_GPU_CGC can't be able to control it.
>>
>> The commit message clearly states "These new GPU_CGC clock
>> gate the existing GPU clock." and "GPU_CGC as well as its parent GPU clock."
>> , I don't perceive any ambiguity, sorry.
>>
>> Frankly, the whole GPUAPB discussion is entirely unrelated and it only stalls
>> application of this bugfix and keeps upstream broken. This is not helping.
>>
>> So unless there is anything in particular that is on-topic and prevents this
>> patch from being applied, it would be good to apply it, otherwise the GPU on
>> MX95 in mainline Linux is not working.
> Hi Marek,
> 
> I’m not opposed to this patch being merged into mainline, but the commit
> message needs to be accurate. the parent CLK_GPU cannot be enabled or
> disabled externally. The last sentence should clearly state:

Look here, this is what you can do with the MX95 SM:

"
 >$ clock.r
...
083: gpuapb               =  on,  133333333Hz
084: gpu                  =  on,  800000000Hz
...
174: gpu_cgc              =  on,  800000000Hz

 >$ clock.w gpu_cgc off
 >$ clock.w gpu off
 >$ clock.w gpuapb off

 >$ clock.r
...
083: gpuapb               = off,  133333333Hz
084: gpu                  = off,  800000000Hz
...
174: gpu_cgc              = off,  800000000Hz
"

Notice how all clock are disabled, including GPU clock.

That does not agree with your statement.

> When the panthor driver enables the GPU core clock, it enables the GPU_CGC.

It also enables all disabled parent clock in the process, which includes 
the GPU clock.

> This ensures the description reflects the actual hardware behavior and
> avoids confusion for future maintainers.
> Thanks for addressing this issue — once the commit message is corrected,
> I’m fine with this going in.

See above.