drm/i915/mst: use max link not sink lane count

The source might not support as many lanes as the sink, or the link
training might have failed at higher lane counts. Take these into
account.

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/cf59530acafaf9258fb643d321ad251b44f34e29.1491485983.git.jani.nikula@intel.com

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index b3df2082eac97e0a2a008b4e69dac2dbdc4f96d9..95f2278700e3aa293a8d425508d3a1811c4ff2ad 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -177,7 +177,7 @@ static int intel_dp_max_common_lane_count(struct intel_dp *intel_dp)
        return min(source_max, sink_max);
 }
 
-static int intel_dp_max_lane_count(struct intel_dp *intel_dp)
+int intel_dp_max_lane_count(struct intel_dp *intel_dp)
 {
        return intel_dp->max_link_lane_count;
 }

diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index 094cbdcbcd6dd4e4c44a009b7d697caae6a17146..40608101cd3a868f4f89c605dfcae29c7cb37791 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -56,7 +56,7 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
         * for MST we always configure max link bw - the spec doesn't
         * seem to suggest we should do otherwise.
         */
-       lane_count = drm_dp_max_lane_count(intel_dp->dpcd);
+       lane_count = intel_dp_max_lane_count(intel_dp);
 
        pipe_config->lane_count = lane_count;
 
@@ -343,7 +343,7 @@ intel_dp_mst_mode_valid(struct drm_connector *connector,
        int max_rate, mode_rate, max_lanes, max_link_clock;
 
        max_link_clock = intel_dp_max_link_rate(intel_dp);
-       max_lanes = drm_dp_max_lane_count(intel_dp->dpcd);
+       max_lanes = intel_dp_max_lane_count(intel_dp);
 
        max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes);
        mode_rate = intel_dp_link_required(mode->clock, bpp);

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index f97603b74a28e4d3e30e9783a152d267dfa539c7..5f6e1aad909d6550f5af56abeb55a0b49555382b 100644 (file)
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1503,6 +1503,7 @@ void intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *co
 void intel_dp_mst_suspend(struct drm_device *dev);
 void intel_dp_mst_resume(struct drm_device *dev);
 int intel_dp_max_link_rate(struct intel_dp *intel_dp);
+int intel_dp_max_lane_count(struct intel_dp *intel_dp);
 int intel_dp_rate_select(struct intel_dp *intel_dp, int rate);
 void intel_dp_hot_plug(struct intel_encoder *intel_encoder);
 void intel_power_sequencer_reset(struct drm_i915_private *dev_priv);