[Intel-gfx] [PATCH 23/29] drm/i915/dp_mst: Enable DSC passthrough

[Imre Deak]

Enable passing through DSC streams to the sink in last branch devices.

Signed-off-by: Imre Deak <imre.d...@intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 26 ++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c 
b/drivers/gpu/drm/i915/display/intel_dp.c
index a7eb31b489947..bb8951f89f61f 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2950,6 +2950,24 @@ intel_dp_sink_set_dsc_decompression(struct 
intel_connector *connector,
                            str_enable_disable(enable));
 }
 
+static void
+intel_dp_sink_set_dsc_passthrough(const struct intel_connector *connector,
+                                 bool enable)
+{
+       struct drm_i915_private *i915 = to_i915(connector->base.dev);
+       struct drm_dp_aux *aux = connector->port ?
+                                connector->port->passthrough_aux : NULL;
+
+       if (!aux)
+               return;
+
+       if (drm_dp_dpcd_writeb(aux, DP_DSC_PASSTHROUGH_EN,
+                              enable ? DP_DSC_PASSTHROUGH_EN : 0) < 0)
+               drm_dbg_kms(&i915->drm,
+                           "Failed to %s sink compression passthrough state\n",
+                           str_enable_disable(enable));
+}
+
 void intel_dp_sink_set_decompression_state(struct intel_connector *connector,
                                           const struct intel_crtc_state 
*crtc_state,
                                           bool enable)
@@ -2962,7 +2980,13 @@ void intel_dp_sink_set_decompression_state(struct 
intel_connector *connector,
        if (drm_WARN_ON(&i915->drm, !connector->dp.dsc_decompression_aux))
                return;
 
-       intel_dp_sink_set_dsc_decompression(connector, enable);
+       if (enable) {
+               intel_dp_sink_set_dsc_passthrough(connector, true);
+               intel_dp_sink_set_dsc_decompression(connector, true);
+       } else {
+               intel_dp_sink_set_dsc_decompression(connector, false);
+               intel_dp_sink_set_dsc_passthrough(connector, false);
+       }
 }
 
 static void
-- 
2.39.2