On Wed, Jul 29, 2015 at 10:18:16PM -0700, Linus Torvalds wrote: > drivers/gpu/drm/drm_atomic_helper.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c > index 5b59d5ad7d1c..aac212297b49 100644 > --- a/drivers/gpu/drm/drm_atomic_helper.c > +++ b/drivers/gpu/drm/drm_atomic_helper.c > @@ -230,10 +230,12 @@ update_connector_routing(struct drm_atomic_state *state, int conn_idx) > } > > connector_state->best_encoder = new_encoder; > - idx = drm_crtc_index(connector_state->crtc); > + if (connector_state->crtc) { > + idx = drm_crtc_index(connector_state->crtc); > > - crtc_state = state->crtc_states[idx]; > - crtc_state->mode_changed = true; > + crtc_state = state->crtc_states[idx]; > + crtc_state->mode_changed = true; > + } This shouldn't happen since if it does we ended up stealing the encoder from the connector itself (we do check for connector_state->crtc earlier) and that would be a bug. I haven't figured out a precise theory but my guess is on the best_encoder selection, and indeed dp mst encoder selection seems to have gone belly up in 4.2 with the bisected commit. I have 4 patches in git://people.freedesktop.org/~danvet/drm fixes-stuff but I couldn't test them yet since no dp mst here and I didn't find anything that would ship faster than 1-2 weeks yet. I'll try to get some other people here to test it meanwhile too. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel