Merge tag 'drm-intel-next-2015-12-04-1' of git://anongit.freedesktop.org/drm-intel into drm-next

This is the "fix igt basic test set issues" edition.
- more PSR fixes from Rodrigo, getting closer
- tons of fifo underrun fixes from Ville
- runtime pm fixes from Imre, Daniel Stone
- fix SDE interrupt handling properly (Jani Nikula)
- hsw/bdw fdi modeset sequence fixes (Ville)
- "don't register bad VGA connectors and fall over" fixes (Ville)
- more fbc fixes from Paulo
- and a grand total of exactly one feature item: Implement dma-buf/fence based
  cross-driver sync in the i915 pageflip path (Alex Goins)

* tag 'drm-intel-next-2015-12-04-1' of git://anongit.freedesktop.org/drm-intel: (70 commits)
  drm/i915: Update DRIVER_DATE to 20151204
  drm/i915/skl: Add SKL GT4 PCI IDs
  Revert "drm/i915: Extend LRC pinning to cover GPU context writeback"
  drm/i915: Correct the Ref clock value for BXT
  drm/i915: Restore skl_gt3 device info
  drm/i915: Fix RPS pointer passed from wait_ioctl to i915_wait_request
  Revert "drm/i915: Remove superfluous NULL check"
  drm/i915: Clean up device info structure definitions
  drm/i915: Remove superfluous NULL check
  drm/i915: Handle cdclk limits on broadwell.
  i915: wait for fence in prepare_plane_fb
  i915: wait for fence in mmio_flip_work_func
  drm/i915: Extend LRC pinning to cover GPU context writeback
  drm/i915/guc: Clean up locks in GuC
  drm/i915: only recompress FBC after flushing a drawing operation
  drm/i915: get rid of FBC {,de}activation messages
  drm/i915: kill fbc.uncompressed_size
  drm/i915: use a single intel_fbc_work struct
  drm/i915: check for FBC planes in the same place as the pipes
  drm/i915: alloc/free the FBC CFB during enable/disable
  ...

1 files changed, 27 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index 912c0ac95f2a..9285fc1e64ee 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -777,11 +777,37 @@ void intel_crt_init(struct drm_device *dev)
 	struct intel_crt *crt;
 	struct intel_connector *intel_connector;
 	struct drm_i915_private *dev_priv = dev->dev_private;
+	i915_reg_t adpa_reg;
+	u32 adpa;
 
 	/* Skip machines without VGA that falsely report hotplug events */
 	if (dmi_check_system(intel_no_crt))
 		return;
 
+	if (HAS_PCH_SPLIT(dev))
+		adpa_reg = PCH_ADPA;
+	else if (IS_VALLEYVIEW(dev))
+		adpa_reg = VLV_ADPA;
+	else
+		adpa_reg = ADPA;
+
+	adpa = I915_READ(adpa_reg);
+	if ((adpa & ADPA_DAC_ENABLE) == 0) {
+		/*
+		 * On some machines (some IVB at least) CRT can be
+		 * fused off, but there's no known fuse bit to
+		 * indicate that. On these machine the ADPA register
+		 * works normally, except the DAC enable bit won't
+		 * take. So the only way to tell is attempt to enable
+		 * it and see what happens.
+		 */
+		I915_WRITE(adpa_reg, adpa | ADPA_DAC_ENABLE |
+			   ADPA_HSYNC_CNTL_DISABLE | ADPA_VSYNC_CNTL_DISABLE);
+		if ((I915_READ(adpa_reg) & ADPA_DAC_ENABLE) == 0)
+			return;
+		I915_WRITE(adpa_reg, adpa);
+	}
+
 	crt = kzalloc(sizeof(struct intel_crt), GFP_KERNEL);
 	if (!crt)
 		return;
@@ -815,12 +841,7 @@ void intel_crt_init(struct drm_device *dev)
 		connector->interlace_allowed = 1;
 	connector->doublescan_allowed = 0;
 
-	if (HAS_PCH_SPLIT(dev))
-		crt->adpa_reg = PCH_ADPA;
-	else if (IS_VALLEYVIEW(dev))
-		crt->adpa_reg = VLV_ADPA;
-	else
-		crt->adpa_reg = ADPA;
+	crt->adpa_reg = adpa_reg;
 
 	crt->base.compute_config = intel_crt_compute_config;
 	if (HAS_PCH_SPLIT(dev) && !HAS_DDI(dev)) {