diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 15a981ef5966..1a510cf58fb5 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -4050,16 +4050,10 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) } static bool -intel_dp_can_mst(struct intel_dp *intel_dp) +intel_dp_sink_can_mst(struct intel_dp *intel_dp) { u8 mstm_cap; - if (!i915_modparams.enable_dp_mst) - return false; - - if (!intel_dp->can_mst) - return false; - if (intel_dp->dpcd[DP_DPCD_REV] < 0x12) return false; @@ -4069,21 +4063,30 @@ intel_dp_can_mst(struct intel_dp *intel_dp) return mstm_cap & DP_MST_CAP; } +static bool +intel_dp_can_mst(struct intel_dp *intel_dp) +{ + return i915_modparams.enable_dp_mst && + intel_dp->can_mst && + intel_dp_sink_can_mst(intel_dp); +} + static void intel_dp_configure_mst(struct intel_dp *intel_dp) { - if (!i915_modparams.enable_dp_mst) - return; + struct intel_encoder *encoder = + &dp_to_dig_port(intel_dp)->base; + bool sink_can_mst = intel_dp_sink_can_mst(intel_dp); + + DRM_DEBUG_KMS("MST support? port %c: %s, sink: %s, modparam: %s\n", + port_name(encoder->port), yesno(intel_dp->can_mst), + yesno(sink_can_mst), yesno(i915_modparams.enable_dp_mst)); if (!intel_dp->can_mst) return; - intel_dp->is_mst = intel_dp_can_mst(intel_dp); - - if (intel_dp->is_mst) - DRM_DEBUG_KMS("Sink is MST capable\n"); - else - DRM_DEBUG_KMS("Sink is not MST capable\n"); + intel_dp->is_mst = sink_can_mst && + i915_modparams.enable_dp_mst; drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, intel_dp->is_mst);