diff options
| author | Imre Deak <imre.deak@intel.com> | 2024-07-22 19:55:02 +0300 |
|---|---|---|
| committer | Imre Deak <imre.deak@intel.com> | 2024-07-31 18:45:59 +0300 |
| commit | e44bc451aa4b08845c238028daafb4eaffb573a3 (patch) | |
| tree | a981c85bc982f183280fef0c792a656662f78e5c | |
| parent | e40fbf616610e33aba9597f278925b4ae8cc806c (diff) | |
drm/i915/dp_mst: Ensure link parameters are up-to-date for a disabled link
As explained in the previous patch, the MST link BW reported by branch
devices during topology probing/path resources enumeration depends on
the link parameters programmed to DPCD to be up-to-date. After a sink is
plugged this is not ensured, as those DPCD values start out zeroed. The
target link parameters (for a subsequent modeset) are the maximum that
is supported, so make sure these maximum values are programmed before the
topology probing.
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240722165503.2084999-14-imre.deak@intel.com
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp.c | 3 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp_mst.c | 31 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp_mst.h | 1 |
3 files changed, 35 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 5523469404f9..09789d62001f 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -4254,6 +4254,9 @@ intel_dp_mst_configure(struct intel_dp *intel_dp) intel_dp->is_mst = intel_dp->mst_detect != DRM_DP_SST; + if (intel_dp->is_mst) + intel_dp_mst_prepare_probe(intel_dp); + drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, intel_dp->is_mst); /* Avoid stale info on the next detect cycle. */ 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); +} diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.h b/drivers/gpu/drm/i915/display/intel_dp_mst.h index 8ca1d599091c..fba76454fa67 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.h +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.h @@ -27,5 +27,6 @@ int intel_dp_mst_atomic_check_link(struct intel_atomic_state *state, struct intel_link_bw_limits *limits); bool intel_dp_mst_crtc_needs_modeset(struct intel_atomic_state *state, struct intel_crtc *crtc); +void intel_dp_mst_prepare_probe(struct intel_dp *intel_dp); #endif /* __INTEL_DP_MST_H__ */ |