From 5bddd17fec58f253cddd0bc9eab2cd9eb1bbab4a Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Thu, 18 Nov 2010 09:32:59 +0800 Subject: [PATCH] drm/i915: Apply a workaround for transitioning from DP on pipe B to HDMI. This workaround only applies to Ironlake. Signed-off-by: Eric Anholt Signed-off-by: Chris Wilson Cc: stable@kernel.org --- drivers/gpu/drm/i915/intel_dp.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 300f64b4238..1d8d068bc47 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1374,6 +1374,7 @@ intel_dp_link_down(struct intel_dp *intel_dp) { struct drm_device *dev = intel_dp->base.base.dev; struct drm_i915_private *dev_priv = dev->dev_private; + struct intel_crtc *intel_crtc = to_intel_crtc(intel_dp->base.base.crtc); uint32_t DP = intel_dp->DP; DRM_DEBUG_KMS("\n"); @@ -1398,6 +1399,26 @@ intel_dp_link_down(struct intel_dp *intel_dp) if (is_edp(intel_dp)) DP |= DP_LINK_TRAIN_OFF; + + if (!HAS_PCH_CPT(dev) && (DP & DP_PIPEB_SELECT)) { + /* 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); } -- 2.46.0