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| author |   Jani Nikula <jani.nikula@intel.com> | 2021-10-11 21:21:43 +0300 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2021-10-12 11:42:08 +0300 |
| commit | 319f4def310cc0851208410e05db325e6c884046 (patch) | |
| tree | 2a6358597bdbb4618b59f193fb777d33a5366132 /drivers/gpu/drm/i915/display | |
| parent | drm/i915/mst: abstract intel_dp_mst_source_support() (diff) | |
| download | linux-dev-319f4def310cc0851208410e05db325e6c884046.tar.xz linux-dev-319f4def310cc0851208410e05db325e6c884046.zip | |
drm/i915/dp: abstract intel_dp_lane_max_vswing_reached()
Add per-lane abstraction for max vswing reached to make follow-up
cleaner, as this one reverses the conditions.
v2: both conditions need to be true, reverse (Ville)
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211011182144.22074-1-jani.nikula@intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/display')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp_link_training.c | 42 |
1 files changed, 25 insertions, 17 deletions
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 1a943ae38a6b..1d4bcb91cd3b 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c @@ -515,29 +515,37 @@ intel_dp_update_link_train(struct intel_dp *intel_dp, return ret == crtc_state->lane_count; } +/* + * FIXME: The DP spec is very confusing here, also the Link CTS spec seems to + * have self contradicting tests around this area. + * + * In lieu of better ideas let's just stop when we've reached the max supported + * vswing with its max pre-emphasis, which is either 2+1 or 3+0 depending on + * whether vswing level 3 is supported or not. + */ +static bool intel_dp_lane_max_vswing_reached(u8 train_set_lane) +{ + u8 v = (train_set_lane & DP_TRAIN_VOLTAGE_SWING_MASK) >> + DP_TRAIN_VOLTAGE_SWING_SHIFT; + u8 p = (train_set_lane & DP_TRAIN_PRE_EMPHASIS_MASK) >> + DP_TRAIN_PRE_EMPHASIS_SHIFT; + + if ((train_set_lane & DP_TRAIN_MAX_SWING_REACHED) == 0) + return false; + + if (v + p != 3) + return false; + + return true; +} + static bool intel_dp_link_max_vswing_reached(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state) { int lane; - /* - * FIXME: The DP spec is very confusing here, also the Link CTS - * spec seems to have self contradicting tests around this area. - * - * In lieu of better ideas let's just stop when we've reached the - * max supported vswing with its max pre-emphasis, which is either - * 2+1 or 3+0 depending on whether vswing level 3 is supported or not. - */ for (lane = 0; lane < crtc_state->lane_count; lane++) { - u8 v = (intel_dp->train_set[lane] & DP_TRAIN_VOLTAGE_SWING_MASK) >> - DP_TRAIN_VOLTAGE_SWING_SHIFT; - u8 p = (intel_dp->train_set[lane] & DP_TRAIN_PRE_EMPHASIS_MASK) >> - DP_TRAIN_PRE_EMPHASIS_SHIFT; - - if ((intel_dp->train_set[lane] & DP_TRAIN_MAX_SWING_REACHED) == 0) - return false; - - if (v + p != 3) + if (!intel_dp_lane_max_vswing_reached(intel_dp->train_set[lane])) return false; } |