diff options
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index f3b6cd5057ea..823355705a5e 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -2517,14 +2517,23 @@ static void intel_dp_enable_port(struct intel_dp *intel_dp) struct drm_device *dev = intel_dp_to_dev(intel_dp); struct drm_i915_private *dev_priv = dev->dev_private; - intel_dp->DP |= DP_PORT_EN; - /* enable with pattern 1 (as per spec) */ _intel_dp_set_link_train(intel_dp, &intel_dp->DP, DP_TRAINING_PATTERN_1); I915_WRITE(intel_dp->output_reg, intel_dp->DP); POSTING_READ(intel_dp->output_reg); + + /* + * Magic for VLV/CHV. We _must_ first set up the register + * without actually enabling the port, and then do another + * write to enable the port. Otherwise link training will + * fail when the power sequencer is freshly used for this port. + */ + intel_dp->DP |= DP_PORT_EN; + + I915_WRITE(intel_dp->output_reg, intel_dp->DP); + POSTING_READ(intel_dp->output_reg); } static void intel_enable_dp(struct intel_encoder *encoder) |