diff options
| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2020-07-09 17:58:45 +0300 |
|---|---|---|
| committer | José Roberto de Souza <jose.souza@intel.com> | 2020-07-13 14:43:56 -0700 |
| commit | a133c6988f7080fb8baf86ecf5161065bec65fb6 (patch) | |
| tree | c50e9ba5ea2b0382e1c6244b30848d3b4f898dfc /drivers/gpu/drm/i915 | |
| parent | e398d7c126c10eb40f87edb6d4ce6dea6c123e7f (diff) | |
| download | linux-a133c6988f7080fb8baf86ecf5161065bec65fb6.tar.bz2 | |
drm/i915: WARN if max vswing/pre-emphasis violates the DP spec
According to the DP spec a DPTX must support vswing/pre-emphasis
up to and including level 2. Level 3 is optional (actually DP 1.4a
seems to make even level 3 mandatory for HBR2/3, while leaving it
optional for RBR/HBR1).
WARN if out encoders' .voltage_max()/.preemph_max() return
an illegal value.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200709145845.18118-1-ville.syrjala@linux.intel.com
Diffstat (limited to 'drivers/gpu/drm/i915')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp_link_training.c | 9 |
1 files changed, 9 insertions, 0 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 2493142a70e9..a23ed7290843 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c @@ -52,6 +52,7 @@ static u8 dp_voltage_max(u8 preemph) void intel_dp_get_adjust_train(struct intel_dp *intel_dp, const u8 link_status[DP_LINK_STATUS_SIZE]) { + struct drm_i915_private *i915 = dp_to_i915(intel_dp); u8 v = 0; u8 p = 0; int lane; @@ -64,12 +65,20 @@ void intel_dp_get_adjust_train(struct intel_dp *intel_dp, } preemph_max = intel_dp->preemph_max(intel_dp); + drm_WARN_ON_ONCE(&i915->drm, + preemph_max != DP_TRAIN_PRE_EMPH_LEVEL_2 && + preemph_max != DP_TRAIN_PRE_EMPH_LEVEL_3); + if (p >= preemph_max) p = preemph_max | DP_TRAIN_MAX_PRE_EMPHASIS_REACHED; v = min(v, dp_voltage_max(p)); voltage_max = intel_dp->voltage_max(intel_dp); + drm_WARN_ON_ONCE(&i915->drm, + voltage_max != DP_TRAIN_VOLTAGE_SWING_LEVEL_2 && + voltage_max != DP_TRAIN_VOLTAGE_SWING_LEVEL_3); + if (v >= voltage_max) v = voltage_max | DP_TRAIN_MAX_SWING_REACHED; |