From ad44c03208e46b83e4ae3269e32c9e524aa71cf8 Mon Sep 17 00:00:00 2001 From: Koba Ko Date: Tue, 22 Sep 2020 14:53:13 +0800 Subject: [PATCH] drm/dp_mst: Retrieve extended DPCD caps for topology manager 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 Reviewed-by: Lyude Paul [added aux name to drm_dbg_kms() call] Signed-off-by: Lyude Paul Link: https://patchwork.freedesktop.org/patch/msgid/20200922065313.4794-1-koba.ko@canonical.com --- drivers/gpu/drm/drm_dp_mst_topology.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index b9c5a98c5c9ce..b4a4bb340910f 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -3536,9 +3536,10 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms WARN_ON(mgr->mst_primary); /* get dpcd info */ - ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, 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, "%s: failed to read DPCD, ret %d\n", + mgr->aux->name, ret); goto out_unlock; }