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path: root/drivers/gpu/drm/display/drm_dp_mst_topology.c
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Diffstat (limited to 'drivers/gpu/drm/display/drm_dp_mst_topology.c')
-rw-r--r--drivers/gpu/drm/display/drm_dp_mst_topology.c20
1 files changed, 13 insertions, 7 deletions
diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
index 03d528209426..c193be3577f7 100644
--- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
@@ -3608,24 +3608,30 @@ fixed20_12 drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr,
EXPORT_SYMBOL(drm_dp_get_vc_payload_bw);
/**
- * drm_dp_read_mst_cap() - check whether or not a sink supports MST
+ * drm_dp_read_mst_cap() - Read the sink's MST mode capability
* @aux: The DP AUX channel to use
* @dpcd: A cached copy of the DPCD capabilities for this sink
*
- * Returns: %True if the sink supports MST, %false otherwise
+ * Returns: enum drm_dp_mst_mode to indicate MST mode capability
*/
-bool drm_dp_read_mst_cap(struct drm_dp_aux *aux,
- const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+enum drm_dp_mst_mode drm_dp_read_mst_cap(struct drm_dp_aux *aux,
+ const u8 dpcd[DP_RECEIVER_CAP_SIZE])
{
u8 mstm_cap;
if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_12)
- return false;
+ return DRM_DP_SST;
if (drm_dp_dpcd_readb(aux, DP_MSTM_CAP, &mstm_cap) != 1)
- return false;
+ return DRM_DP_SST;
+
+ if (mstm_cap & DP_MST_CAP)
+ return DRM_DP_MST;
+
+ if (mstm_cap & DP_SINGLE_STREAM_SIDEBAND_MSG)
+ return DRM_DP_SST_SIDEBAND_MSG;
- return mstm_cap & DP_MST_CAP;
+ return DRM_DP_SST;
}
EXPORT_SYMBOL(drm_dp_read_mst_cap);