1 files changed, 25 insertions, 16 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 77e729d4e4f..1ab842c6032 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -636,6 +636,19 @@ render_ring_add_request(struct intel_ring_buffer *ring,
 }
 
 static u32
+gen6_ring_get_seqno(struct intel_ring_buffer *ring)
+{
+	struct drm_device *dev = ring->dev;
+
+	/* Workaround to force correct ordering between irq and seqno writes on
+	 * ivb (and maybe also on snb) by reading from a CS register (like
+	 * ACTHD) before reading the status page. */
+	if (IS_GEN7(dev))
+		intel_ring_get_active_head(ring);
+	return intel_read_status_page(ring, I915_GEM_HWS_INDEX);
+}
+
+static u32
 ring_get_seqno(struct intel_ring_buffer *ring)
 {
 	return intel_read_status_page(ring, I915_GEM_HWS_INDEX);
@@ -792,17 +805,6 @@ ring_add_request(struct intel_ring_buffer *ring,
 }
 
 static bool
-gen7_blt_ring_get_irq(struct intel_ring_buffer *ring)
-{
-	/* The BLT ring on IVB appears to have broken synchronization
-	 * between the seqno write and the interrupt, so that the
-	 * interrupt appears first.  Returning false here makes
-	 * i915_wait_request() do a polling loop, instead.
-	 */
-	return false;
-}
-
-static bool
 gen6_ring_get_irq(struct intel_ring_buffer *ring, u32 gflag, u32 rflag)
 {
 	struct drm_device *dev = ring->dev;
@@ -811,6 +813,12 @@ gen6_ring_get_irq(struct intel_ring_buffer *ring, u32 gflag, u32 rflag)
 	if (!dev->irq_enabled)
 	       return false;
 
+	/* It looks like we need to prevent the gt from suspending while waiting
+	 * for an notifiy irq, otherwise irqs seem to get lost on at least the
+	 * blt/bsd rings on ivb. */
+	if (IS_GEN7(dev))
+		gen6_gt_force_wake_get(dev_priv);
+
 	spin_lock(&ring->irq_lock);
 	if (ring->irq_refcount++ == 0) {
 		ring->irq_mask &= ~rflag;
@@ -835,6 +843,9 @@ gen6_ring_put_irq(struct intel_ring_buffer *ring, u32 gflag, u32 rflag)
 		ironlake_disable_irq(dev_priv, gflag);
 	}
 	spin_unlock(&ring->irq_lock);
+
+	if (IS_GEN7(dev))
+		gen6_gt_force_wake_put(dev_priv);
 }
 
 static bool
@@ -1341,7 +1352,7 @@ static const struct intel_ring_buffer gen6_bsd_ring = {
 	.write_tail		= gen6_bsd_ring_write_tail,
 	.flush			= gen6_ring_flush,
 	.add_request		= gen6_add_request,
-	.get_seqno		= ring_get_seqno,
+	.get_seqno		= gen6_ring_get_seqno,
 	.irq_get		= gen6_bsd_ring_get_irq,
 	.irq_put		= gen6_bsd_ring_put_irq,
 	.dispatch_execbuffer	= gen6_ring_dispatch_execbuffer,
@@ -1476,7 +1487,7 @@ static const struct intel_ring_buffer gen6_blt_ring = {
 	.write_tail		= ring_write_tail,
 	.flush			= blt_ring_flush,
 	.add_request		= gen6_add_request,
-	.get_seqno		= ring_get_seqno,
+	.get_seqno		= gen6_ring_get_seqno,
 	.irq_get		= blt_ring_get_irq,
 	.irq_put		= blt_ring_put_irq,
 	.dispatch_execbuffer	= gen6_ring_dispatch_execbuffer,
@@ -1499,6 +1510,7 @@ int intel_init_render_ring_buffer(struct drm_device *dev)
 		ring->flush = gen6_render_ring_flush;
 		ring->irq_get = gen6_render_ring_get_irq;
 		ring->irq_put = gen6_render_ring_put_irq;
+		ring->get_seqno = gen6_ring_get_seqno;
 	} else if (IS_GEN5(dev)) {
 		ring->add_request = pc_render_add_request;
 		ring->get_seqno = pc_render_get_seqno;
@@ -1577,8 +1589,5 @@ int intel_init_blt_ring_buffer(struct drm_device *dev)
 
 	*ring = gen6_blt_ring;
 
-	if (IS_GEN7(dev))
-		ring->irq_get = gen7_blt_ring_get_irq;
-
 	return intel_init_ring_buffer(dev, ring);
 }