diff options
Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_dp_mst.c')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp_mst.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index 19c8b6878b03..faee7af0a8a4 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -43,6 +43,7 @@ #include "intel_dp_hdcp.h" #include "intel_dp_mst.h" #include "intel_dp_tunnel.h" +#include "intel_dp_link_training.h" #include "intel_dpio_phy.h" #include "intel_hdcp.h" #include "intel_hotplug.h" @@ -2031,3 +2032,33 @@ bool intel_dp_mst_crtc_needs_modeset(struct intel_atomic_state *state, return false; } + +/** + * intel_dp_mst_prepare_probe - Prepare an MST link for topology probing + * @intel_dp: DP port object + * + * Prepare an MST link for topology probing, programming the target + * link parameters to DPCD. This step is a requirement of the enumaration + * of path resources during probing. + */ +void intel_dp_mst_prepare_probe(struct intel_dp *intel_dp) +{ + int link_rate = intel_dp_max_link_rate(intel_dp); + int lane_count = intel_dp_max_lane_count(intel_dp); + u8 rate_select; + u8 link_bw; + + if (intel_dp->link_trained) + return; + + if (intel_mst_probed_link_params_valid(intel_dp, link_rate, lane_count)) + return; + + intel_dp_compute_rate(intel_dp, link_rate, &link_bw, &rate_select); + + intel_dp_link_training_set_mode(intel_dp, link_rate, false); + intel_dp_link_training_set_bw(intel_dp, link_bw, rate_select, lane_count, + drm_dp_enhanced_frame_cap(intel_dp->dpcd)); + + intel_mst_set_probed_link_params(intel_dp, link_rate, lane_count); +} |