drm/i915: Don't copy sink rates either

Once we've read the rates from the sink we don't have to mess with them,
so the caller can just look at the stored rates without doing extra
copies. If the sink doesn't support the new link rate stuff, we just
point the caller at the default_rates[] array.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Sonika Jindal <sonika.jindal@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_dp.c

@@ -1141,22 +1141,16 @@ hsw_dp_set_ddi_pll_sel(struct intel_crtc_state *pipe_config, int link_bw)
 }
 
 static int
-intel_read_sink_rates(struct intel_dp *intel_dp, int *sink_rates)
+intel_dp_sink_rates(struct intel_dp *intel_dp, const int **sink_rates)
 {
-	struct drm_device *dev = intel_dp_to_dev(intel_dp);
-
-	if (INTEL_INFO(dev)->gen >= 9 && intel_dp->supported_rates[0]) {
-		/*
-		 * Receiver supports only main-link rate selection by
-		 * link rate table method, so read link rates from
-		 * supported_link_rates
-		 */
-		memcpy(sink_rates, intel_dp->supported_rates,
-		       sizeof(intel_dp->supported_rates));
-
+	if (intel_dp->num_supported_rates) {
+		*sink_rates = intel_dp->supported_rates;
 		return intel_dp->num_supported_rates;
 	}
-	return 0;
+
+	*sink_rates = default_rates;
+
+	return (intel_dp_max_link_bw(intel_dp) >> 3) + 1;
 }
 
 static int
@@ -1266,12 +1260,12 @@ intel_dp_compute_config(struct intel_encoder *encoder,
 	int max_clock;
 	int bpp, mode_rate;
 	int link_avail, link_clock;
-	int sink_rates[8];
+	const int *sink_rates;
 	int supported_rates[8] = {0};
 	const int *source_rates;
 	int source_len, sink_len, supported_len;
 
-	sink_len = intel_read_sink_rates(intel_dp, sink_rates);
+	sink_len = intel_dp_sink_rates(intel_dp, &sink_rates);
 
 	source_len = intel_dp_source_rates(intel_dp, &source_rates);