Re: [PATCH v2 4/9] drm/panthor: Implement optional reset

Marek Vasut
2025-03-24T19:09:17Z

On 3/24/25 9:43 AM, Boris Brezillon wrote:

[...]

>> @@ -563,6 +585,7 @@ int panthor_device_suspend(struct device *dev)
>>
>> panthor_devfreq_suspend(ptdev);
>>
>> + reset_control_assert(ptdev->resets);
>
> Hm, that might be the cause of the fast reset issue (which is a fast
> resume more than a fast reset BTW): if you re-assert the reset line on
> runtime suspend, I guess this causes a full GPU reset, and the MCU ends
> up in a state where it needs a slow reset (all data sections reset to
> their initial state). Can you try to move the reset_control_[de]assert
> to the unplug/init functions?
The reset on the MX95 is not really a reset, it is clear-only
set-never-again bit which goes only one way, the "unreset" way, so I
don't think this has any impact. Also, I commented this out already and
it made no difference. I will give the second part of our suggestion a
try in the next few days though, and also try the updated downstream
firmware blobs (sigh).