diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 51fbc5e33c55..6218fa97aa1e 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -34,6 +34,14 @@ #include "i915_trace.h" #include "intel_drv.h" +static inline int ring_space(struct intel_ring_buffer *ring) +{ + int space = (ring->head & HEAD_ADDR) - (ring->tail + 8); + if (space < 0) + space += ring->size; + return space; +} + static u32 i915_gem_get_seqno(struct drm_device *dev) { drm_i915_private_t *dev_priv = dev->dev_private; @@ -204,11 +212,9 @@ static int init_ring_common(struct intel_ring_buffer *ring) if (!drm_core_check_feature(ring->dev, DRIVER_MODESET)) i915_kernel_lost_context(ring->dev); else { - ring->head = I915_READ_HEAD(ring) & HEAD_ADDR; + ring->head = I915_READ_HEAD(ring); ring->tail = I915_READ_TAIL(ring) & TAIL_ADDR; - ring->space = ring->head - (ring->tail + 8); - if (ring->space < 0) - ring->space += ring->size; + ring->space = ring_space(ring); } return 0; @@ -921,7 +927,7 @@ static int intel_wrap_ring_buffer(struct intel_ring_buffer *ring) } ring->tail = 0; - ring->space = ring->head - 8; + ring->space = ring_space(ring); return 0; } @@ -933,20 +939,22 @@ int intel_wait_ring_buffer(struct intel_ring_buffer *ring, int n) unsigned long end; u32 head; + /* If the reported head position has wrapped or hasn't advanced, + * fallback to the slow and accurate path. + */ + head = intel_read_status_page(ring, 4); + if (head > ring->head) { + ring->head = head; + ring->space = ring_space(ring); + if (ring->space >= n) + return 0; + } + trace_i915_ring_wait_begin (dev); end = jiffies + 3 * HZ; do { - /* If the reported head position has wrapped or hasn't advanced, - * fallback to the slow and accurate path. - */ - head = intel_read_status_page(ring, 4); - if (head < ring->actual_head) - head = I915_READ_HEAD(ring); - ring->actual_head = head; - ring->head = head & HEAD_ADDR; - ring->space = ring->head - (ring->tail + 8); - if (ring->space < 0) - ring->space += ring->size; + ring->head = I915_READ_HEAD(ring); + ring->space = ring_space(ring); if (ring->space >= n) { trace_i915_ring_wait_end(dev); return 0; diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index 61d5220c4b58..6d6fde85a636 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -47,7 +47,6 @@ struct intel_ring_buffer { struct drm_device *dev; struct drm_i915_gem_object *obj; - u32 actual_head; u32 head; u32 tail; int space;