diff options
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 38 |
1 files changed, 37 insertions, 1 deletions
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c index 9221b6690a4a..a6d551ff89d1 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c @@ -344,12 +344,48 @@ dm_dp_mst_detect(struct drm_connector *connector, { struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector); struct amdgpu_dm_connector *master = aconnector->mst_port; + struct drm_dp_mst_port *port = aconnector->port; + int connection_status; if (drm_connector_is_unregistered(connector)) return connector_status_disconnected; - return drm_dp_mst_detect_port(connector, ctx, &master->mst_mgr, + connection_status = drm_dp_mst_detect_port(connector, ctx, &master->mst_mgr, aconnector->port); + + if (port->pdt != DP_PEER_DEVICE_NONE && !port->dpcd_rev) { + uint8_t dpcd_rev; + int ret; + + ret = drm_dp_dpcd_readb(&port->aux, DP_DP13_DPCD_REV, &dpcd_rev); + + if (ret == 1) { + port->dpcd_rev = dpcd_rev; + + /* Could be DP1.2 DP Rx case*/ + if (!dpcd_rev) { + ret = drm_dp_dpcd_readb(&port->aux, DP_DPCD_REV, &dpcd_rev); + + if (ret == 1) + port->dpcd_rev = dpcd_rev; + } + + if (!dpcd_rev) + DRM_DEBUG_KMS("Can't decide DPCD revision number!"); + } + + /* + * Could be legacy sink, logical port etc on DP1.2. + * Will get Nack under these cases when issue remote + * DPCD read. + */ + if (ret != 1) + DRM_DEBUG_KMS("Can't access DPCD"); + } else if (port->pdt == DP_PEER_DEVICE_NONE) { + port->dpcd_rev = 0; + } + + return connection_status; } static int dm_dp_mst_atomic_check(struct drm_connector *connector, |