From: Ville Syrjälä <[email protected]> Currently we don't clflush on pin_to_display if the bo is already UC/WT and is not in the CPU write domain. This causes problems with pwrite since pwrite doesn't change the write domain, and it avoids clflushing on UC/WT buffers on LLC platforms unless the buffer is currently being scanned out.
Fix the problem by marking the cache dirty and adjusting i915_gem_object_set_cache_level() to clflush when the cache is dirty even if the cache_level doesn't change. My last attempt [1] at fixing this via write domain frobbing was shot down, but now with the cache_dirty flag we can do things in a nicer way. [1] http://lists.freedesktop.org/archives/intel-gfx/2014-November/055390.html v2: Drop the I915_CACHE_NONE/WT checks from pwrite Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=86422 Testcase: igt/kms_pwrite_crc Testcase: igt/gem_pwrite_snooped Signed-off-by: Ville Syrjälä <[email protected]> --- drivers/gpu/drm/i915/i915_gem.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 73293b4..f828dc7 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1005,12 +1005,14 @@ out: if (!needs_clflush_after && obj->base.write_domain != I915_GEM_DOMAIN_CPU) { if (i915_gem_clflush_object(obj, obj->pin_display)) - i915_gem_chipset_flush(dev); + needs_clflush_after = true; } } if (needs_clflush_after) i915_gem_chipset_flush(dev); + else + obj->cache_dirty = true; intel_fb_obj_flush(obj, false, ORIGIN_CPU); return ret; @@ -3639,10 +3641,10 @@ int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj, { struct drm_device *dev = obj->base.dev; struct i915_vma *vma, *next; - int ret; + int ret = 0; if (obj->cache_level == cache_level) - return 0; + goto out; if (i915_gem_obj_is_pinned(obj)) { DRM_DEBUG("can not change the cache level of pinned objects\n"); @@ -3687,6 +3689,7 @@ int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj, vma->node.color = cache_level; obj->cache_level = cache_level; +out: if (obj->cache_dirty && obj->base.write_domain != I915_GEM_DOMAIN_CPU && cpu_write_needs_clflush(obj)) { -- 2.4.6 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
