diff options
| -rw-r--r-- | drivers/gpu/drm/i915/i915_dma.c | 2 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/intel_ringbuffer.c | 4 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/intel_ringbuffer.h | 11 |
3 files changed, 14 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index 80ed75117b6..8f63cd5de4b 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -141,7 +141,7 @@ void i915_kernel_lost_context(struct drm_device * dev) ring->head = I915_READ_HEAD(ring) & HEAD_ADDR; ring->tail = I915_READ_TAIL(ring) & TAIL_ADDR; - ring->space = ring->head - (ring->tail + 8); + ring->space = ring->head - (ring->tail + I915_RING_FREE_SPACE); if (ring->space < 0) ring->space += ring->size; diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index bc7cf7c6310..2346b920bd8 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -45,7 +45,7 @@ struct pipe_control { static inline int ring_space(struct intel_ring_buffer *ring) { - int space = (ring->head & HEAD_ADDR) - (ring->tail + 8); + int space = (ring->head & HEAD_ADDR) - (ring->tail + I915_RING_FREE_SPACE); if (space < 0) space += ring->size; return space; @@ -1227,7 +1227,7 @@ static int intel_ring_wait_request(struct intel_ring_buffer *ring, int n) if (request->tail == -1) continue; - space = request->tail - (ring->tail + 8); + space = request->tail - (ring->tail + I915_RING_FREE_SPACE); if (space < 0) space += ring->size; if (space >= n) { diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index d4b7416fa1b..526182ed0c6 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -1,6 +1,17 @@ #ifndef _INTEL_RINGBUFFER_H_ #define _INTEL_RINGBUFFER_H_ +/* + * Gen2 BSpec "1. Programming Environment" / 1.4.4.6 "Ring Buffer Use" + * Gen3 BSpec "vol1c Memory Interface Functions" / 2.3.4.5 "Ring Buffer Use" + * Gen4+ BSpec "vol1c Memory Interface and Command Stream" / 5.3.4.5 "Ring Buffer Use" + * + * "If the Ring Buffer Head Pointer and the Tail Pointer are on the same + * cacheline, the Head Pointer must not be greater than the Tail + * Pointer." + */ +#define I915_RING_FREE_SPACE 64 + struct intel_hw_status_page { u32 *page_addr; unsigned int gfx_addr; |