a little late but: i915 does have this hack (or rather-possible_crtcs with MST in i915 has been broken for a while and got fixed, but had to get reverted because of this issue), it's where this originally came from. On Wed, 2019-10-09 at 17:01 +0200, Daniel Vetter wrote: > On Fri, Sep 27, 2019 at 11:27:41AM -0400, Sean Paul wrote: > > On Thu, Sep 26, 2019 at 06:51:07PM -0400, Lyude Paul wrote: > > > This commit is seperate from the previous one to make it easier to > > > revert in the future. Basically, there's multiple userspace applications > > > that interpret possible_crtcs very wrong: > > > > > > https://gitlab.freedesktop.org/xorg/xserver/merge_requests/277 > > > https://gitlab.gnome.org/GNOME/mutter/issues/759 > > > > > > While work is ongoing to fix these issues in userspace, we need to > > > report ->possible_crtcs incorrectly for now in order to avoid > > > introducing a regression in in userspace. Once these issues get fixed, > > > this commit should be reverted. > > > > > > Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx> > > > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > --- > > > drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 11 +++++++++++ > > > 1 file changed, 11 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c > > > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c > > > index b404f1ae6df7..fe8ac801d7a5 100644 > > > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c > > > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c > > > @@ -4807,6 +4807,17 @@ static int amdgpu_dm_crtc_init(struct > > > amdgpu_display_manager *dm, > > > if (!acrtc->mst_encoder) > > > goto fail; > > > > > > + /* > > > + * FIXME: This is a hack to workaround the following issues: > > > + * > > > + * https://gitlab.gnome.org/GNOME/mutter/issues/759 > > > + * https://gitlab.freedesktop.org/xorg/xserver/merge_requests/277 > > > + * > > > + * One these issues are closed, this should be removed > > > > Even when these issues are closed, we'll still be introducing a regression > > if we > > revert this change. Time for actually_possible_crtcs? :) > > > > You also might want to briefly explain the u/s bug in case the links go > > sour. > > > > > + */ > > > + acrtc->mst_encoder->base.possible_crtcs = > > > + amdgpu_dm_get_encoder_crtc_mask(dm->adev); > > > > Why don't we put this hack in amdgpu_dm_dp_create_fake_mst_encoder()? > > If we don't have the same hack for i915 mst I think we shouldn't merge > this ... broken userspace is broken. > -Daniel -- Cheers, Lyude Paul _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
