diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2011-01-04 18:42:07 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2011-01-11 20:42:53 +0000 |
| commit | 63256ec5347fb2344a42adbae732b90603c92f35 (patch) | |
| tree | 5b018e93f38f9e90f3b07beeaac4af08122c5876 /drivers | |
| parent | 759010728b1323aec03c5baae13fde8f76e44a99 (diff) | |
drm/i915: Enforce write ordering through the GTT
We need to ensure that writes through the GTT land before any
modification to the MMIO registers and so must impose a mandatory write
barrier when flushing the GTT domain. This was revealed by relaxing the
write ordering by experimentally mapping the registers and the GATT as
write-combining.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem.c | 14 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem_execbuffer.c | 3 |
2 files changed, 16 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index c79c0b62ef60..f9c093c08d58 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2393,6 +2393,12 @@ i915_gem_object_flush_fence(struct drm_i915_gem_object *obj, obj->last_fenced_ring = NULL; } + /* Ensure that all CPU reads are completed before installing a fence + * and all writes before removing the fence. + */ + if (obj->base.read_domains & I915_GEM_DOMAIN_GTT) + mb(); + return 0; } @@ -2833,10 +2839,16 @@ i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *obj) if (obj->base.write_domain != I915_GEM_DOMAIN_GTT) return; - /* No actual flushing is required for the GTT write domain. Writes + /* No actual flushing is required for the GTT write domain. Writes * to it immediately go to main memory as far as we know, so there's * no chipset flush. It also doesn't land in render cache. + * + * However, we do have to enforce the order so that all writes through + * the GTT land before any writes to the device, such as updates to + * the GATT itself. */ + wmb(); + i915_gem_release_mmap(obj); old_write_domain = obj->base.write_domain; diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 61129e6759eb..0d42de42868c 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -725,6 +725,9 @@ i915_gem_execbuffer_flush(struct drm_device *dev, if (flush_domains & I915_GEM_DOMAIN_CPU) intel_gtt_chipset_flush(); + if (flush_domains & I915_GEM_DOMAIN_GTT) + wmb(); + if ((flush_domains | invalidate_domains) & I915_GEM_GPU_DOMAINS) { for (i = 0; i < I915_NUM_RINGS; i++) if (flush_rings & (1 << i)) |