On Mon, Nov 23, 2015 at 10:25:28AM +0100, Maarten Lankhorst wrote: > Op 13-11-15 om 14:28 schreef Ander Conselvan De Oliveira: > > On Thu, 2015-11-12 at 14:58 +0100, Maarten Lankhorst wrote: > >> Op 12-11-15 om 14:37 schreef Ander Conselvan De Oliveira: > >>> On Wed, 2015-11-11 at 15:36 +0100, Maarten Lankhorst wrote: > >>>> When disable_noatomic is called plane_mask is not reliable yet, > >>>> and plane_state->visible = true even after disabling the primary plane. > >>> So the stale value of plane_state->visible causes a subsequent modeset to > >>> enable > >>> the primary again? > >> Probably not because it would get recalculated in calc_changes, but it should > >> really be set to false afterwards. > > So basically I didn't understand how the wrong value of plane_state->visible > > causes the bug that was mentioned. I think a brief explanation in the commit > > message would be good. > Well, apply with git am --scissors. Same patch but mentioning this. > > Is this better? > ---->8----- > > When disable_noatomic is called plane_mask is not correct yet, > and plane_state->visible = true is left as true after disabling > the primary plane. > > Other planes are already disabled as part of crtc sanitization, only the > primary is left active. But the plane_mask is not updated here. It gets updated > during fb takeover in modeset_gem_init, or set to the new value on resume. > > This means that to disable the primary plane 1 << drm_plane_index(primary) > needs to be used. > > Afterwards because the crtc is no longer active it's forbidden to keep > plane_state->visible set, or a WARN_ON in intel_plane_atomic_calc_changes > triggers. There are other code points that rely on accurate plane_state->visible > too, so make sure the bool is cleared. Oh dear is this a mess :( As a bugfix this is Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> But we need to bring a _lot_ more sanity to this in -next. Would probably be better if we keep the primary plane state all consistent, and then clear both visible and plane_mask when fb reconstruction fails. Also, some WARN_ON to bitch about inconsistency between plane_mask and ->visible in the disable code paths would be good I think. -Daniel > > > The other planes are already disabled in intel_sanitize_crtc, so > they don't have to be handled here. > > Cc: stable@xxxxxxxxxxxxxxx #v4.3, v4.2? > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92655 > Tested-by: Tomas Mezzadra <tmezzadra@xxxxxxxxx> > Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> > --- > drivers/gpu/drm/i915/intel_display.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index b5f7493213b7..bc3282ab5ed2 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -6267,9 +6267,11 @@ static void intel_crtc_disable_noatomic(struct drm_crtc *crtc) > WARN_ON(intel_crtc->unpin_work); > > intel_pre_disable_primary(crtc); > + > + intel_crtc_disable_planes(crtc, 1 << drm_plane_index(crtc->primary)); > + to_intel_plane_state(crtc->primary->state)->visible = false; > } > > - intel_crtc_disable_planes(crtc, crtc->state->plane_mask); > dev_priv->display.crtc_disable(crtc); > intel_crtc->active = false; > intel_update_watermarks(crtc); > -- 2.1.0 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
