Re: [PATCH v2] drm/doc: document front-buffer rendering

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Thu, May 01, 2025 at 11:25:11AM +0000, Simon Ser wrote:
> Ah, sorry, I missed this message.
> 
> On Monday, April 14th, 2025 at 15:28, Ville Syrjälä <ville.syrjala@linux.intel.com> wrote:
> 
> > Should probably add a caveat that this needs to be a sync commit/flip.
> > The way the async flip was specified for atomic explicitly requires the
> > driver to ignore the plane when the fb doesn't change.
> 
> I don't believe so. Async flip should work fine with same FB.

The way you specified this means the kernel has to explicitly ignore
it because not all planes may support async flips. We can't generally
mix async and sync stuff into the same commit.

> The kernel
> will only ignore other props if they match their previous value.
> 
> > Also use dirtyfb instead if you don't want to get throttled to the
> > vrefresh rate. Tthough I think with some drivers you might get
> > throttled even with dirtyfb...
> 
> Like Simona, I'm really not a fan of mixing atomic and non-atomic. It's
> caused issues in the past, e.g. ChromeOS forcing amdgpu to reject atomic
> commits which could cause future cursor IOCTLs to fail.

-- 
Ville Syrjälä
Intel