diff options
| author | Imre Deak <imre.deak@intel.com> | 2024-06-10 19:49:28 +0300 |
|---|---|---|
| committer | Imre Deak <imre.deak@intel.com> | 2024-06-13 21:26:49 +0300 |
| commit | 73afc1e2fd1d3b3f086a4ba1714c8d1ecc40d4f9 (patch) | |
| tree | a53bc99cab81c46847521ce9ea45f98cdf9d7b61 /drivers/gpu/drm/i915 | |
| parent | e3e70d08409086ada2c864373d9d8b8ef9a55936 (diff) | |
| download | linux-73afc1e2fd1d3b3f086a4ba1714c8d1ecc40d4f9.tar.xz | |
drm/i915/dp_mst: Enable link training fallback for MST
Reduce the link parameters after a link training failure for MST
outputs, similarly to how this is done for SST.
For now allow the reduction only by staying in the 8b/10b vs. 128b/132b
mode. Enabling the mode switch is left for a follow-up patchset, after
taking measures ensuring that the mode switch happens properly. In
particular a rediscovery of the whole MST topology may be required for
such a switch, see the References below.
Link: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/10970
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240610164933.2947366-17-imre.deak@intel.com
Diffstat (limited to 'drivers/gpu/drm/i915')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp.c | 6 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp_link_training.c | 13 |
2 files changed, 5 insertions, 14 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 500090674c7a..795498382254 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -5887,11 +5887,7 @@ intel_dp_detect(struct drm_connector *connector, intel_dp_mst_configure(intel_dp); - /* - * TODO: Reset link params when switching to MST mode, until MST - * supports link training fallback params. - */ - if (intel_dp->reset_link_params || intel_dp->is_mst) { + if (intel_dp->reset_link_params) { intel_dp_reset_link_params(intel_dp); intel_dp->reset_link_params = false; } diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c index e106a9e6ea3b..af6536936550 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c @@ -1124,6 +1124,10 @@ static int reduce_link_rate(struct intel_dp *intel_dp, int current_rate) new_rate = intel_dp_common_rate(intel_dp, rate_index - 1); + /* TODO: Make switching from UHBR to non-UHBR rates work. */ + if (drm_dp_is_uhbr_rate(current_rate) != drm_dp_is_uhbr_rate(new_rate)) + return -1; + return new_rate; } @@ -1141,15 +1145,6 @@ static int intel_dp_get_link_train_fallback_values(struct intel_dp *intel_dp, int new_link_rate; int new_lane_count; - /* - * TODO: Enable fallback on MST links once MST link compute can handle - * the fallback params. - */ - if (intel_dp->is_mst) { - lt_err(intel_dp, DP_PHY_DPRX, "Link Training Unsuccessful\n"); - return -1; - } - if (intel_dp_is_edp(intel_dp) && !intel_dp->use_max_params) { lt_dbg(intel_dp, DP_PHY_DPRX, "Retrying Link training for eDP with max parameters\n"); |