[PATCH v4 10/11] drm/i915: Update bits per component for display info

[Mika Kahola]

DisplayPort branch device may define max supported bits per
component. Update display info based on this value if bpc
is defined.

Signed-off-by: Mika Kahola <mika.kahola at intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 1b94347..ad3ff37 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3932,6 +3932,17 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
 {
        uint8_t *dpcd = intel_dp->dpcd;
        uint8_t type;
+       uint8_t cap[4];
+
+       if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT) {
+               int bpc;
+
+               drm_dp_downstream_port_cap(&intel_dp->aux, dpcd, cap);
+               bpc = drm_dp_downstream_max_bpc(dpcd, cap);
+
+               if (bpc > 0)
+                       intel_dp->attached_connector->base.display_info.bpc = 
bpc;
+       }

        if (!intel_dp_get_dpcd(intel_dp))
                return connector_status_disconnected;
@@ -3969,6 +3980,7 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
                        return connector_status_unknown;
        }

+
        /* Anything else is out of spec, warn and ignore */
        DRM_DEBUG_KMS("Broken DP branch device, ignoring\n");
        return connector_status_disconnected;
-- 
1.9.1