diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 0daefca5cbb8..a4d80314e7f8 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -213,7 +213,7 @@ intel_dp_mode_valid(struct drm_connector *connector, return MODE_PANEL; } - /* only refuse the mode on non eDP since we have seen some wierd eDP panels + /* only refuse the mode on non eDP since we have seen some weird eDP panels which are outside spec tolerances but somehow work by magic */ if (!is_edp(intel_dp) && (intel_dp_link_required(connector->dev, intel_dp, mode->clock) @@ -1470,7 +1470,8 @@ intel_dp_link_down(struct intel_dp *intel_dp) 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); + struct drm_crtc *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. @@ -1485,7 +1486,19 @@ intel_dp_link_down(struct intel_dp *intel_dp) /* Changes to enable or select take place the vblank * after being written. */ - intel_wait_for_vblank(dev, intel_crtc->pipe); + if (crtc == NULL) { + /* We can arrive here never having been attached + * to a CRTC, for instance, due to inheriting + * random state from the BIOS. + * + * If the pipe is not running, play safe and + * wait for the clocks to stabilise before + * continuing. + */ + POSTING_READ(intel_dp->output_reg); + msleep(50); + } else + intel_wait_for_vblank(dev, to_intel_crtc(crtc)->pipe); } I915_WRITE(intel_dp->output_reg, DP & ~DP_PORT_EN); |