drm/i915: fix calculation of eDP signal levels on Sandybridge
Some voltage swing/pre-emphasis level use the same value on eDP
Sandybridge, like 400mv_0db and 600mv_0db are with the same value
of (0x0 << 22). So, fix them, and point out the value if it isn't
a supported voltage swing/pre-emphasis level.
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index c768e30e..1f4242b 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1153,18 +1153,27 @@
static uint32_t
intel_gen6_edp_signal_levels(uint8_t train_set)
{
- switch (train_set & (DP_TRAIN_VOLTAGE_SWING_MASK|DP_TRAIN_PRE_EMPHASIS_MASK)) {
+ int signal_levels = train_set & (DP_TRAIN_VOLTAGE_SWING_MASK |
+ DP_TRAIN_PRE_EMPHASIS_MASK);
+ switch (signal_levels) {
case DP_TRAIN_VOLTAGE_SWING_400 | DP_TRAIN_PRE_EMPHASIS_0:
- return EDP_LINK_TRAIN_400MV_0DB_SNB_B;
+ case DP_TRAIN_VOLTAGE_SWING_600 | DP_TRAIN_PRE_EMPHASIS_0:
+ return EDP_LINK_TRAIN_400_600MV_0DB_SNB_B;
+ case DP_TRAIN_VOLTAGE_SWING_400 | DP_TRAIN_PRE_EMPHASIS_3_5:
+ return EDP_LINK_TRAIN_400MV_3_5DB_SNB_B;
case DP_TRAIN_VOLTAGE_SWING_400 | DP_TRAIN_PRE_EMPHASIS_6:
- return EDP_LINK_TRAIN_400MV_6DB_SNB_B;
+ case DP_TRAIN_VOLTAGE_SWING_600 | DP_TRAIN_PRE_EMPHASIS_6:
+ return EDP_LINK_TRAIN_400_600MV_6DB_SNB_B;
case DP_TRAIN_VOLTAGE_SWING_600 | DP_TRAIN_PRE_EMPHASIS_3_5:
- return EDP_LINK_TRAIN_600MV_3_5DB_SNB_B;
+ case DP_TRAIN_VOLTAGE_SWING_800 | DP_TRAIN_PRE_EMPHASIS_3_5:
+ return EDP_LINK_TRAIN_600_800MV_3_5DB_SNB_B;
case DP_TRAIN_VOLTAGE_SWING_800 | DP_TRAIN_PRE_EMPHASIS_0:
- return EDP_LINK_TRAIN_800MV_0DB_SNB_B;
+ case DP_TRAIN_VOLTAGE_SWING_1200 | DP_TRAIN_PRE_EMPHASIS_0:
+ return EDP_LINK_TRAIN_800_1200MV_0DB_SNB_B;
default:
- DRM_DEBUG_KMS("Unsupported voltage swing/pre-emphasis level\n");
- return EDP_LINK_TRAIN_400MV_0DB_SNB_B;
+ DRM_DEBUG_KMS("Unsupported voltage swing/pre-emphasis level:"
+ "0x%x\n", signal_levels);
+ return EDP_LINK_TRAIN_400_600MV_0DB_SNB_B;
}
}