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

[Marek Vasut]

On 12/31/25 4:06 AM, Rain Yang wrote:
> On Tue, Dec 30, 2025 at 03:17:44PM +0100, Marek Vasut wrote:
>> 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.
> 
> Hi Marek,
> Based on the instructions you gave, I’d put it this way, even though the
> CLK_GPU clock can only be controlled internally.
> 
> I’m fine with your patch now.

Thank you