diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_ringbuffer.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_ringbuffer.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 56bc95c056d..2de0e45464c 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -785,6 +785,14 @@ int intel_init_ring_buffer(struct drm_device *dev, if (ret) goto err_unmap; + /* Workaround an erratum on the i830 which causes a hang if + * the TAIL pointer points to within the last 2 cachelines + * of the buffer. + */ + ring->effective_size = ring->size; + if (IS_I830(ring->dev)) + ring->effective_size -= 128; + return 0; err_unmap: @@ -827,8 +835,7 @@ void intel_cleanup_ring_buffer(struct intel_ring_buffer *ring) static int intel_wrap_ring_buffer(struct intel_ring_buffer *ring) { unsigned int *virt; - int rem; - rem = ring->size - ring->tail; + int rem = ring->size - ring->tail; if (ring->space < rem) { int ret = intel_wait_ring_buffer(ring, rem); @@ -895,7 +902,7 @@ int intel_ring_begin(struct intel_ring_buffer *ring, int n = 4*num_dwords; int ret; - if (unlikely(ring->tail + n > ring->size)) { + if (unlikely(ring->tail + n > ring->effective_size)) { ret = intel_wrap_ring_buffer(ring); if (unlikely(ret)) return ret; |