Commit 2dcab875 authored Nov 03, 2020 by Koba Ko Committed by Lyude Paul Nov 10, 2020

Revert "drm/dp_mst: Retrieve extended DPCD caps for topology manager"



This reverts commit ad44c032.

Currently DRM driver assume the source device caps is higher than the MST device
caps. With this commit, this statement would be broken.

e.g. the source device only support DP1.2 and the mst device support DP1.4.

Signed-off-by: Koba Ko <koba.ko@canonical.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201103034907.72129-1-koba.ko@canonical.com

parent 23d6ab1d

drivers/gpu/drm/drm_dp_mst_topology.c

+3 −4

Original line number	Diff line number	Diff line
		@@ -3686,10 +3686,9 @@ 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_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);
		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");
		goto out_unlock;
		}

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