From 20fbb14b0826023128b174dd0f255375764a04c6 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Tue, 19 Mar 2024 11:12:49 +0200 Subject: [PATCH] drm/i915/mst: improve debug logging of DP MST mode detect MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Rename intel_dp_can_mst() to intel_dp_mst_detect(), and move all DP MST detect debug logging there. Debug log the sink's MST capability, including single-stream sideband messaging support, and the decision whether to enable MST mode or not. Do this regardless of whether we're actually enabling MST or not. We need to detect MST in intel_dp_detect_dpcd() before the earlier returns, but try not to change the logic otherwise. v2: - Use "MST", "SST w/ sideband messaging", and "SST" for logging (Ville) - Return MST mode from intel_dp_mst_detect() - Do MST detect before early returns from intel_dp_detect_dpcd() Cc: Arun R Murthy Cc: Ville Syrjälä Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/db08536daec0a6062539319d71c10ee1277e3876.1710839496.git.jani.nikula@intel.com Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/display/intel_dp.c | 52 ++++++++++++++++++------- 1 file changed, 37 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 3fb9a5ac1551b..1b5e8a680b1c5 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -4039,31 +4039,50 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) intel_dp->downstream_ports) == 0; } -static bool -intel_dp_can_mst(struct intel_dp *intel_dp) +static const char *intel_dp_mst_mode_str(enum drm_dp_mst_mode mst_mode) +{ + if (mst_mode == DRM_DP_MST) + return "MST"; + else if (mst_mode == DRM_DP_SST_SIDEBAND_MSG) + return "SST w/ sideband messaging"; + else + return "SST"; +} + +static enum drm_dp_mst_mode +intel_dp_mst_detect(struct intel_dp *intel_dp) { struct drm_i915_private *i915 = dp_to_i915(intel_dp); + struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base; + enum drm_dp_mst_mode sink_mst_mode; + enum drm_dp_mst_mode mst_detect; + + sink_mst_mode = drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd); + + if (i915->display.params.enable_dp_mst && + intel_dp_mst_source_support(intel_dp) && + sink_mst_mode == DRM_DP_MST) + mst_detect = DRM_DP_MST; + else + mst_detect = DRM_DP_SST; - return i915->display.params.enable_dp_mst && - intel_dp_mst_source_support(intel_dp) && - drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd) == DRM_DP_MST; + drm_dbg_kms(&i915->drm, + "[ENCODER:%d:%s] MST support: port: %s, sink: %s, modparam: %s -> enable: %s\n", + encoder->base.base.id, encoder->base.name, + str_yes_no(intel_dp_mst_source_support(intel_dp)), + intel_dp_mst_mode_str(sink_mst_mode), + str_yes_no(i915->display.params.enable_dp_mst), + intel_dp_mst_mode_str(mst_detect)); + + return mst_detect; } static void intel_dp_configure_mst(struct intel_dp *intel_dp) { struct drm_i915_private *i915 = dp_to_i915(intel_dp); - struct intel_encoder *encoder = - &dp_to_dig_port(intel_dp)->base; bool sink_can_mst = drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd) == DRM_DP_MST; - drm_dbg_kms(&i915->drm, - "[ENCODER:%d:%s] MST support: port: %s, sink: %s, modparam: %s\n", - encoder->base.base.id, encoder->base.name, - str_yes_no(intel_dp_mst_source_support(intel_dp)), - str_yes_no(sink_can_mst), - str_yes_no(i915->display.params.enable_dp_mst)); - if (!intel_dp_mst_source_support(intel_dp)) return; @@ -5420,6 +5439,7 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp) { struct drm_i915_private *i915 = dp_to_i915(intel_dp); struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); + enum drm_dp_mst_mode mst_detect; u8 *dpcd = intel_dp->dpcd; u8 type; @@ -5431,6 +5451,8 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp) if (!intel_dp_get_dpcd(intel_dp)) return connector_status_disconnected; + mst_detect = intel_dp_mst_detect(intel_dp); + /* if there's no downstream port, we're done */ if (!drm_dp_is_branch(dpcd)) return connector_status_connected; @@ -5442,7 +5464,7 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp) connector_status_connected : connector_status_disconnected; } - if (intel_dp_can_mst(intel_dp)) + if (mst_detect == DRM_DP_MST) return connector_status_connected; /* If no HPD, poke DDC gently */ -- 2.30.2