Hi, sorry I lost track of this until just now. Comments down below: On Fri, 2020-09-11 at 11:44 +0800, Koba Ko wrote: > As per DP-1.3, First check DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT. > If DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT is 1, read the DP_DP13_DPCD_REV to > get the faster capability. > If DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT is 0, read DP_DPCD_REV. > > Signed-off-by: Koba Ko <koba.ko@xxxxxxxxxxxxx> > Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx> > --- > Changelog: > 1. Adjust the commit message. > 2. use drm_dbg_kms instead and print the return code. > --- > drivers/gpu/drm/drm_dp_mst_topology.c | 14 +++----------- > 1 file changed, 3 insertions(+), 11 deletions(-) > > diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c > b/drivers/gpu/drm/drm_dp_mst_topology.c > index 7753c718ddf9..63f8809b9aa4 100644 > --- a/drivers/gpu/drm/drm_dp_mst_topology.c > +++ b/drivers/gpu/drm/drm_dp_mst_topology.c > @@ -3671,8 +3671,6 @@ EXPORT_SYMBOL(drm_dp_read_mst_cap); > int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, > bool mst_state) > { > int ret = 0; > - u8 dpcd_ext = 0; > - unsigned int dpcd_offset = 0; > struct drm_dp_mst_branch *mstb = NULL; > > mutex_lock(&mgr->payload_lock); > @@ -3686,17 +3684,11 @@ int drm_dp_mst_topology_mgr_set_mst(struct > drm_dp_mst_topology_mgr *mgr, bool ms > struct drm_dp_payload reset_pay; > > WARN_ON(mgr->mst_primary); > - drm_dp_dpcd_read(mgr->aux, > - DP_TRAINING_AUX_RD_INTERVAL, > - &dpcd_ext, sizeof(dpcd_ext)); > - > - dpcd_offset = > - ((dpcd_ext & DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT) > ? DP_DP13_DPCD_REV : DP_DPCD_REV); Uh, are you sure you formatted this patch correctly? None of these hunks are present upstream, this looks like it's a diff for the previous version of this patch that you sent out > > /* get dpcd info */ > - ret = drm_dp_dpcd_read(mgr->aux, dpcd_offset, mgr->dpcd, > DP_RECEIVER_CAP_SIZE); > - if (ret != DP_RECEIVER_CAP_SIZE) { > - DRM_DEBUG_KMS("failed to read DPCD\n"); > + ret = drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd); > + if (ret < 0) { > + drm_dbg_kms(mgr->dev, "failed to read DPCD, ret %d\n", > ret); > goto out_unlock; > } > -- Cheers, Lyude Paul (she/her) Software Engineer at Red Hat _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel