Merge "drm: Check dp extended receiver capabilities" (c5ac9792) · Commits · e / devices / android_kernel_xiaomi_nabu

drivers/gpu/drm/drm_dp_mst_topology.c

+16 −1

Original line number	Diff line number	Diff line
		@@ -2155,6 +2155,8 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
		{
		int ret = 0;
		struct drm_dp_mst_branch *mstb = NULL;
		u8 buf;
		u32 offset = DP_DPCD_REV;

		mutex_lock(&mgr->lock);
		if (mst_state == mgr->mst_state)
		@@ -2165,8 +2167,21 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
		if (mst_state) {
		WARN_ON(mgr->mst_primary);

		ret = drm_dp_dpcd_read(mgr->aux, DP_TRAINING_AUX_RD_INTERVAL,
		&buf, 1);
		if (ret != 1) {
		DRM_DEBUG_KMS("failed to read aux rd interval\n");
		ret = -EINVAL;
		goto out_unlock;
		}

		/* check for EXTENDED_RECEIVER_CAPABILITY_FIELD_PRESENT */
		if (buf & BIT(7))
		offset = 0x2200;

		/* get dpcd info */
		ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
		ret = drm_dp_dpcd_read(mgr->aux, offset, mgr->dpcd,
		DP_RECEIVER_CAP_SIZE);
		if (ret != DP_RECEIVER_CAP_SIZE) {
		DRM_DEBUG_KMS("failed to read DPCD\n");
		goto out_unlock;