Re: [PATCH] drm/i915/display: Allow async flips on planes with no framebuffer changes

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

On Sat, Jul 19, 2025 at 02:16:22AM +0200, Xaver Hugl wrote:
> Am Do., 10. Juli 2025 um 22:21 Uhr schrieb Ville Syrjälä
> <ville.syrjala@linux.intel.com>:
> >
> > On Mon, Jul 07, 2025 at 03:41:20PM +0000, Naveen Kumar wrote:
> > > Allow asynchronous page flips on planes that either lack a framebuffer or
> > > retain the same framebuffer, as long as no plane properties are modified.
> > >
> > > This avoids unnecessary failures in async flip paths when the update is
> > > effectively a no-op, improving compatibility with some compositors.
> >
> > IMO what we want to do is make the drm core filter out all the garbage
> > from the commit. That way the driver would only see the planes that are
> > supposed to actually participate in the async flip.
> 
> That sounds like a good goal, but I think it'll need some extra care
> to avoid regressions. For example, "no-op" pageflips must still
> trigger pageflip events, and affect the refresh rate with adaptive
> sync.

Not for async commit via the atomic ioctl. That's where I'd want
the filtering.

For sync commit nothing can really be filtered by the core code
because side effects must be observed, and only the driver knows
what all the side effects are.

-- 
Ville Syrjälä
Intel