Comme=
nt # 19
on bug 11065=
9
from Nicholas Kazlauskas<=
/a>
(In reply to tempel.julian from comment #18)
> Huh, with modesetting driver, those patches elim=
inate the stutter when new
> windows are shown. Does the xf86-video-amdgpu driver need adjustments =
for
> this?
It should eliminate stuttering for that case in xf86-video-amdgpu if it's t=
he
problem I think it is (double buffering the cursor).
>=20
> However, turning on nightlight in Plasma Wayland still causes stutter,=
which
> is not there with amdgpu.dc=3D0.
1. Gamma updates are slow updates that do a lot of register programming.
Nightlight and RedShift issue a lot of these updates.
2. Gamma updates, like everything that isn't a cursor update, currently tar=
get
the next vblank period.
3. If the pageflip is in a separate commit or update than the gamma update,
then it'll need to wait for the gamma update to finish and for the next vbl=
ank
interval. If this takes too long then we might miss the next vblank interval
and have to wait for the one after that.
I think it's a combination of these 3 issues. Even though it's Wayland and
should be using the full atomic API, I'm not sure if plasma is actually iss=
uing
all that state in the same commit or not.
My guess would be no, since you're seeing the stuttering. We do have a bug =
with
(2) for legacy gamma updates, since there isn't really any reason those sho=
uld
be waiting for the next flip / vblank other than to be consistent with the =
rest
of the atomic commit framework.
> RedShift btw. is completely broken with amdgpu.d=
c=3D1 + modesetting DDX, it
> simply has no effect anymore (not related to the experimental atomic
> modesetting patches).
Not sure what the issue here would be. Gamma seems to work fine for legacy =
and
atomic on amdgpu (we pass the IGT tests for this) and it works fine in lega=
cy
desktops like GNOME on Xorg with the xf86-video-amdgpu DDX.
Was this still on Plasma, but on X?