From d4e16b8b0365f3b6f19c45e7c4e6b643b5a67786 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Tue, 19 Mar 2024 11:12:50 +0200 Subject: [PATCH] drm/i915/mst: abstract choosing the MST mode to use MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Clarify the conditions for choosing the MST mode to use by adding a new function intel_dp_mst_mode_choose(). This also prepares for being able to extend the MST modes to single-stream sideband messaging. Cc: Arun R Murthy Cc: Ville Syrjälä Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/f626144f10b03d4609ff38a29bac013ecf3aca4e.1710839496.git.jani.nikula@intel.com Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/display/intel_dp.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 1b5e8a680b1c..c253be068e51 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -4049,6 +4049,24 @@ static const char *intel_dp_mst_mode_str(enum drm_dp_mst_mode mst_mode) return "SST"; } +static enum drm_dp_mst_mode +intel_dp_mst_mode_choose(struct intel_dp *intel_dp, + enum drm_dp_mst_mode sink_mst_mode) +{ + struct drm_i915_private *i915 = dp_to_i915(intel_dp); + + if (!i915->display.params.enable_dp_mst) + return DRM_DP_SST; + + if (!intel_dp_mst_source_support(intel_dp)) + return DRM_DP_SST; + + if (sink_mst_mode == DRM_DP_SST_SIDEBAND_MSG) + return DRM_DP_SST; + + return sink_mst_mode; +} + static enum drm_dp_mst_mode intel_dp_mst_detect(struct intel_dp *intel_dp) { @@ -4059,12 +4077,7 @@ intel_dp_mst_detect(struct intel_dp *intel_dp) 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; + mst_detect = intel_dp_mst_mode_choose(intel_dp, sink_mst_mode); drm_dbg_kms(&i915->drm, "[ENCODER:%d:%s] MST support: port: %s, sink: %s, modparam: %s -> enable: %s\n", -- 2.25.1