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

Boris Brezillon boris.brezillon at collabora.com
Tue Mar 25 00:43:49 PDT 2025


On Tue, 25 Mar 2025 00:37:59 +0100
Marek Vasut <marex at 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.




More information about the linux-arm-kernel mailing list