I think the problem here is that application A can set the FB and then application B can use getfb2 (say ffmpeg). https://lists.freedesktop.org/archives/dri-devel/2021-January/292761.html would be my alternative patch. (I'm not good at detecting the effects of tearing apparently but tested this avoids the pageflip failure by debug-prints) On Thu, Dec 31, 2020 at 9:52 PM Mario Kleiner <mario.kleiner.de@xxxxxxxxx> wrote: > > Commit 816853f9dc4057b6c7ee3c45ca9bd5905 ("drm/amd/display: Set new > format info for converted metadata.") may fix the getfb2 ioctl, but > in exchange it completely breaks all pageflipping for classic user > space, e.g., XOrg, as tested with both amdgpu-ddx and modesetting-ddx. > This leads to massive tearing, broken visual timing/timestamping etc. > > Reason is that the classic pageflip ioctl doesn't allow a fb format > change during flip, and at least X uses classic pageflip ioctl and no > atomic modesetting api at all. > > As one attempted workaround, only set the new format info for converted > metadata if the calling client isn't X. Not sure if this is the best > way, or if a better check would not be "not all atomic clients" or > similar? In any case it works for XOrg X-Server. Checking the ddx > code of intel-ddx/modesetting-ddx/amdgpu-ddx as well as grepping over > Mesa doesn't show any users of the getfb2 ioctl(), so the need for this > format info assignment seems to be more the exception than the rule? > > Fixes: 816853f9dc40 ("drm/amd/display: Set new format info for converted metadata.") > Cc: Bas Nieuwenhuizen <bas@xxxxxxxxxxxxxxxxxxx> > Cc: Alex Deucher <alexander.deucher@xxxxxxx> > Signed-off-by: Mario Kleiner <mario.kleiner.de@xxxxxxxxx> > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > index f764803c53a4..cb414b3d327a 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > @@ -828,7 +828,8 @@ static int convert_tiling_flags_to_modifier(struct amdgpu_framebuffer *afb) > if (!format_info) > return -EINVAL; > > - afb->base.format = format_info; > + if (afb->base.comm[0] != 'X') > + afb->base.format = format_info; > } > } > > -- > 2.25.1 > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
