drm/i915: Fix MST link rate handling

Now that intel_dp_max_link_bw() no longer considers the source
restrictions we may try to enable MST with 5.4GHz even when the source
doesn't support it. To fix that switch the code over to handle the link
rate in the same way as the SST code handles it.

Signed-off-by: Ville Syrjälä <[email protected]>
Reviewed-by: Sonika Jindal <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>

1 files changed, 13 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index be124928ca14..7e6f12597a6c 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -38,7 +38,7 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
 	struct intel_dp *intel_dp = &intel_dig_port->dp;
 	struct drm_device *dev = encoder->base.dev;
 	int bpp;
-	int lane_count, slots;
+	int lane_count, slots, rate;
 	struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
 	struct intel_connector *found = NULL, *intel_connector;
 	int mst_pbn;
@@ -52,11 +52,21 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
 	 * seem to suggest we should do otherwise.
 	 */
 	lane_count = drm_dp_max_lane_count(intel_dp->dpcd);
-	intel_dp->link_bw = intel_dp_max_link_bw(intel_dp);
+
+	rate = intel_dp_max_link_rate(intel_dp);
+
+	if (intel_dp->num_supported_rates) {
+		intel_dp->link_bw = 0;
+		intel_dp->rate_select = intel_dp_rate_select(intel_dp, rate);
+	} else {
+		intel_dp->link_bw = drm_dp_link_rate_to_bw_code(rate);
+		intel_dp->rate_select = 0;
+	}
+
 	intel_dp->lane_count = lane_count;
 
 	pipe_config->pipe_bpp = 24;
-	pipe_config->port_clock = drm_dp_bw_code_to_link_rate(intel_dp->link_bw);
+	pipe_config->port_clock = rate;
 
 	for_each_intel_connector(dev, intel_connector) {
 		if (intel_connector->new_encoder == encoder) {