diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 300f64b4238b..df648cb4c296 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1376,6 +1376,9 @@ intel_dp_link_down(struct intel_dp *intel_dp) struct drm_i915_private *dev_priv = dev->dev_private; uint32_t DP = intel_dp->DP; + if ((I915_READ(intel_dp->output_reg) & DP_PORT_EN) == 0) + return; + DRM_DEBUG_KMS("\n"); if (is_edp(intel_dp)) { @@ -1398,6 +1401,28 @@ intel_dp_link_down(struct intel_dp *intel_dp) if (is_edp(intel_dp)) DP |= DP_LINK_TRAIN_OFF; + + if (!HAS_PCH_CPT(dev) && + I915_READ(intel_dp->output_reg) & DP_PIPEB_SELECT) { + struct intel_crtc *intel_crtc = to_intel_crtc(intel_dp->base.base.crtc); + /* Hardware workaround: leaving our transcoder select + * set to transcoder B while it's off will prevent the + * corresponding HDMI output on transcoder A. + * + * Combine this with another hardware workaround: + * transcoder select bit can only be cleared while the + * port is enabled. + */ + DP &= ~DP_PIPEB_SELECT; + I915_WRITE(intel_dp->output_reg, DP); + + /* Changes to enable or select take place the vblank + * after being written. + */ + intel_wait_for_vblank(intel_dp->base.base.dev, + intel_crtc->pipe); + } + I915_WRITE(intel_dp->output_reg, DP & ~DP_PORT_EN); POSTING_READ(intel_dp->output_reg); } |