diff options
| -rw-r--r-- | shared-core/i915_dma.c | 24 | ||||
| -rw-r--r-- | shared-core/i915_drv.h | 10 |
2 files changed, 34 insertions, 0 deletions
diff --git a/shared-core/i915_dma.c b/shared-core/i915_dma.c index fa73cd29..1fc617d1 100644 --- a/shared-core/i915_dma.c +++ b/shared-core/i915_dma.c @@ -69,6 +69,30 @@ int i915_wait_ring(struct drm_device * dev, int n, const char *caller) return -EBUSY; } +#if I915_RING_VALIDATE +/** + * Validate the cached ring tail value + * + * If the X server writes to the ring and DRM doesn't + * reload the head and tail pointers, it will end up writing + * data to the wrong place in the ring, causing havoc. + */ +void i915_ring_validate(struct drm_device *dev, const char *func, int line) +{ + drm_i915_private_t *dev_priv = dev->dev_private; + drm_i915_ring_buffer_t *ring = &(dev_priv->ring); + u32 tail = I915_READ(LP_RING+RING_TAIL) & HEAD_ADDR; + u32 head = I915_READ(LP_RING+RING_HEAD) & HEAD_ADDR; + + if (tail != ring->tail) { + DRM_ERROR("%s:%d head sw %x, hw %x. tail sw %x hw %x\n", + func, line, + ring->head, head, ring->tail, tail); + BUG_ON(1); + } +} +#endif + void i915_kernel_lost_context(struct drm_device * dev) { drm_i915_private_t *dev_priv = dev->dev_private; diff --git a/shared-core/i915_drv.h b/shared-core/i915_drv.h index 029c39a0..e217b789 100644 --- a/shared-core/i915_drv.h +++ b/shared-core/i915_drv.h @@ -473,14 +473,23 @@ extern void intel_fini_chipset_flush_compat(struct drm_device *dev); #define I915_WRITE16(reg,val) DRM_WRITE16(dev_priv->mmio_map, (reg), (val)) #define I915_VERBOSE 0 +#define I915_RING_VALIDATE 0 #define RING_LOCALS unsigned int outring, ringmask, outcount; \ volatile char *virt; +#if I915_RING_VALIDATE +void i915_ring_validate(struct drm_device *dev, const char *func, int line); +#define I915_RING_DO_VALIDATE(dev) i915_ring_validate(dev, __FUNCTION__, __LINE__) +#else +#define I915_RING_DO_VALIDATE(dev) +#endif + #define BEGIN_LP_RING(n) do { \ if (I915_VERBOSE) \ DRM_DEBUG("BEGIN_LP_RING(%d)\n", \ (n)); \ + I915_RING_DO_VALIDATE(dev); \ if (dev_priv->ring.space < (n)*4) \ i915_wait_ring(dev, (n)*4, __FUNCTION__); \ outcount = 0; \ @@ -499,6 +508,7 @@ extern void intel_fini_chipset_flush_compat(struct drm_device *dev); #define ADVANCE_LP_RING() do { \ if (I915_VERBOSE) DRM_DEBUG("ADVANCE_LP_RING %x\n", outring); \ + I915_RING_DO_VALIDATE(dev); \ dev_priv->ring.tail = outring; \ dev_priv->ring.space -= outcount * 4; \ I915_WRITE(LP_RING + RING_TAIL, outring); \ |