[PATCH v2 2/5] drm/1915: ringbuffer wait for idle function

[Ben Widawsky <ben@bwidawsk.net>]

Added a new function which waits for the ringbuffer space to be equal to
(total - 8). This is the empty condition of the ringbuffer, and
equivalent to head==tail.

Also modified two users of this functionality elsewhere in the code.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_dma.c         |    2 +-
 drivers/gpu/drm/i915/intel_ringbuffer.c |    2 +-
 drivers/gpu/drm/i915/intel_ringbuffer.h |    6 ++++++
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index e33d9be..cdca465 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -563,7 +563,7 @@ static int i915_quiescent(struct drm_device *dev)
 	struct intel_ring_buffer *ring = LP_RING(dev->dev_private);
 
 	i915_kernel_lost_context(dev);
-	return intel_wait_ring_buffer(ring, ring->size - 8);
+	return intel_wait_ring_idle(ring);
 }
 
 static int i915_flush_ioctl(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 445f27e..0b83059 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -893,7 +893,7 @@ void intel_cleanup_ring_buffer(struct intel_ring_buffer *ring)
 
 	/* Disable the ring buffer. The ring must be idle at this point */
 	dev_priv = ring->dev->dev_private;
-	ret = intel_wait_ring_buffer(ring, ring->size - 8);
+	ret = intel_wait_ring_idle(ring);
 	I915_WRITE_CTL(ring, 0);
 
 	drm_core_ioremapfree(&ring->map, ring->dev);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 3430686..30d0437 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -143,7 +143,13 @@ intel_read_status_page(struct intel_ring_buffer *ring,
 }
 
 void intel_cleanup_ring_buffer(struct intel_ring_buffer *ring);
+
 int __must_check intel_wait_ring_buffer(struct intel_ring_buffer *ring, int n);
+static inline int intel_wait_ring_idle(struct intel_ring_buffer *ring)
+{
+	return intel_wait_ring_buffer(ring, ring->space - 8);
+}
+
 int __must_check intel_ring_begin(struct intel_ring_buffer *ring, int n);
 
 static inline void intel_ring_emit(struct intel_ring_buffer *ring,
-- 
1.7.3.4