drm/i915: Fix incorrect intel_ring_begin size in BSD ringbuffer.

The ring_begin API was taking a number of bytes, while all of our
other begin/end macros take number of dwords.  Change the API over to
dwords to prevent future bugs.

Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 5 insertions, 4 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index cea4f1a8709..a3cac5791d7 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -94,7 +94,7 @@ render_ring_flush(struct drm_device *dev,
 #if WATCH_EXEC
                 DRM_INFO("%s: queue flush %08x to ring\n", __func__, cmd);
 #endif
-                intel_ring_begin(dev, ring, 8);
+                intel_ring_begin(dev, ring, 2);
                 intel_ring_emit(dev, ring, cmd);
                 intel_ring_emit(dev, ring, MI_NOOP);
                 intel_ring_advance(dev, ring);
@@ -358,7 +358,7 @@ bsd_ring_flush(struct drm_device *dev,
                 u32     invalidate_domains,
                 u32     flush_domains)
 {
-        intel_ring_begin(dev, ring, 8);
+        intel_ring_begin(dev, ring, 2);
         intel_ring_emit(dev, ring, MI_FLUSH);
         intel_ring_emit(dev, ring, MI_NOOP);
         intel_ring_advance(dev, ring);
@@ -721,8 +721,9 @@ int intel_wait_ring_buffer(struct drm_device *dev,
 }
 
 void intel_ring_begin(struct drm_device *dev,
-                struct intel_ring_buffer *ring, int n)
+                struct intel_ring_buffer *ring, int num_dwords)
 {
+        int n = 4*num_dwords;
         if (unlikely(ring->tail + n > ring->size))
                 intel_wrap_ring_buffer(dev, ring);
         if (unlikely(ring->space < n))
@@ -752,7 +753,7 @@ void intel_fill_struct(struct drm_device *dev,
 {
         unsigned int *virt = ring->virtual_start + ring->tail;
         BUG_ON((len&~(4-1)) != 0);
-        intel_ring_begin(dev, ring, len);
+        intel_ring_begin(dev, ring, len/4);
         memcpy(virt, data, len);
         ring->tail += len;
         ring->tail &= ring->size - 1;