Quoting Ville Syrjala (2021-02-16 16:00:35) > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > Populate conn_state->max_bpc with something sensible from the start. > Otherwise it's possible that we get to compute_sink_pipe_bpp() with > max_bpc==0. > > The specific scenario goes as follows: > 1. Initial connector state allocated with max_bpc==0 > 2. Trigger a modeset on the crtc feeding the connector, without > actually adding the connector to the commit > 3. drm_atomic_connector_check() is skipped because the > connector has not yet been added, hence conn_state->max_bpc > retains its current value > 4. drm_atomic_helper_check_modeset() -> > drm_atomic_add_affected_connectors() -> the connector > is now part of the commit > 5. compute_baseline_pipe_bpp() -> MISSING_CASE(max_bpc==0) > > Note that pipe_bpp itself may not be populated on pre-g4x machines, > in which case we just fall back to max_bpc==8 and let .compute_config() > limit the resulting pipe_bpp further if necessary. > > Cc: Daniel Vetter <daniel@xxxxxxxx> > Reported-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Tested-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
