Merge tag 'drm-intel-fixes-2014-06-17' of git://anongit.freedesktop.org/drm-intel into drm-next

First round of fixes for 3.16-rc, mostly cc: stable, and the vt/vgacon
fixes from Daniel [1] to avoid hangs and unclaimed register errors on
module load/reload.

* tag 'drm-intel-fixes-2014-06-17' of git://anongit.freedesktop.org/drm-intel:
  drm/i915/bdw: remove erroneous chv specific workarounds from bdw code
  drm/i915: fix possible refcount leak when resetting forcewake
  drm/i915: Reorder semaphore deadlock check
  drm/i95: Initialize active ring->pid to -1
  drm/i915: set backlight duty cycle after backlight enable for gen4
  drm/i915: Avoid div-by-zero when pixel_multiplier is zero
  drm/i915: Disable FBC by default also on Haswell and later
  drm/i915: Kick out vga console
  drm/i915: Fixup global gtt cleanup
  vt: Don't ignore unbind errors in vt_unbind
  vt: Fix up unregistration of vt drivers
  vt: Fix replacement console check when unbinding

1 files changed, 14 insertions, 4 deletions

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 6f8017a..267f069 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -2847,10 +2847,14 @@ static int semaphore_passed(struct intel_engine_cs *ring)
 	struct intel_engine_cs *signaller;
 	u32 seqno, ctl;
 
-	ring->hangcheck.deadlock = true;
+	ring->hangcheck.deadlock++;
 
 	signaller = semaphore_waits_for(ring, &seqno);
-	if (signaller == NULL || signaller->hangcheck.deadlock)
+	if (signaller == NULL)
+		return -1;
+
+	/* Prevent pathological recursion due to driver bugs */
+	if (signaller->hangcheck.deadlock >= I915_NUM_RINGS)
 		return -1;
 
 	/* cursory check for an unkickable deadlock */
@@ -2858,7 +2862,13 @@ static int semaphore_passed(struct intel_engine_cs *ring)
 	if (ctl & RING_WAIT_SEMAPHORE && semaphore_passed(signaller) < 0)
 		return -1;
 
-	return i915_seqno_passed(signaller->get_seqno(signaller, false), seqno);
+	if (i915_seqno_passed(signaller->get_seqno(signaller, false), seqno))
+		return 1;
+
+	if (signaller->hangcheck.deadlock)
+		return -1;
+
+	return 0;
 }
 
 static void semaphore_clear_deadlocks(struct drm_i915_private *dev_priv)
@@ -2867,7 +2877,7 @@ static void semaphore_clear_deadlocks(struct drm_i915_private *dev_priv)
 	int i;
 
 	for_each_ring(ring, dev_priv, i)
-		ring->hangcheck.deadlock = false;
+		ring->hangcheck.deadlock = 0;
 }
 
 static enum intel_ring_hangcheck_action