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

Marek Vasut
2025-03-25T13:52:10Z

On 3/25/25 8:43 AM, Boris Brezillon wrote:
> On Tue, 25 Mar 2025 00:37:59 +0100
> Marek Vasut <marex@denx.de> wrote:
>
>> 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?
>> Is it correct to assume , that if I remove all reset_control_assert()
>> calls (and keep only the _deassert() calls), the slow resume problem
>> should go away too ?
>
> Yeah, dropping the _assert()s should do the trick.
Hmmm, no, that does not help. I was hoping maybe NXP can chime in and
suggest something too ?