4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lyude Paul <lyude@xxxxxxxxxx> commit c02ba4ef16eefe663fdefcccaa57fad32d5481bf upstream. Since we need to be able to allow DPMS on->off prop changes after an MST port has disappeared from the system, we need to be able to make sure we can compute a config for the resulting atomic commit. Currently this is impossible when the port has disappeared, since the VCPI slot searching we try to do in intel_dp_mst_compute_config() will fail with -EINVAL. Since the only commits we want to allow on no-longer-present MST ports are ones that shut off display hardware, we already know that no VCPI allocations are needed. So, hardcode the VCPI slot count to 0 when intel_dp_mst_compute_config() is called on an MST port that's gone. Changes since V4: - Don't use mst_port_gone at all, just check whether or not the drm connector is registered - Daniel Vetter Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx> Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://patchwork.freedesktop.org/patch/msgid/20181008232437.5571-5-lyude@xxxxxxxxxx (cherry picked from commit f67207d78ceaf98b7531bc22df6f21328559c8d4) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/intel_dp_mst.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) --- a/drivers/gpu/drm/i915/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/intel_dp_mst.c @@ -38,11 +38,11 @@ static bool intel_dp_mst_compute_config( struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base); struct intel_digital_port *intel_dig_port = intel_mst->primary; struct intel_dp *intel_dp = &intel_dig_port->dp; - struct intel_connector *connector = - to_intel_connector(conn_state->connector); + struct drm_connector *connector = conn_state->connector; + void *port = to_intel_connector(connector)->port; struct drm_atomic_state *state = pipe_config->base.state; int bpp; - int lane_count, slots; + int lane_count, slots = 0; const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode; int mst_pbn; bool reduce_m_n = drm_dp_has_quirk(&intel_dp->desc, @@ -70,17 +70,23 @@ static bool intel_dp_mst_compute_config( pipe_config->port_clock = intel_dp_max_link_rate(intel_dp); - if (drm_dp_mst_port_has_audio(&intel_dp->mst_mgr, connector->port)) + if (drm_dp_mst_port_has_audio(&intel_dp->mst_mgr, port)) pipe_config->has_audio = true; mst_pbn = drm_dp_calc_pbn_mode(adjusted_mode->crtc_clock, bpp); pipe_config->pbn = mst_pbn; - slots = drm_dp_atomic_find_vcpi_slots(state, &intel_dp->mst_mgr, - connector->port, mst_pbn); - if (slots < 0) { - DRM_DEBUG_KMS("failed finding vcpi slots:%d\n", slots); - return false; + /* Zombie connectors can't have VCPI slots */ + if (READ_ONCE(connector->registered)) { + slots = drm_dp_atomic_find_vcpi_slots(state, + &intel_dp->mst_mgr, + port, + mst_pbn); + if (slots < 0) { + DRM_DEBUG_KMS("failed finding vcpi slots:%d\n", + slots); + return false; + } } intel_link_compute_m_n(bpp, lane_count,
