From 23f54483980cea980af37e436ff4e6701aadce12 Mon Sep 17 00:00:00 2001 From: Ben Widawsky Date: Wed, 11 Sep 2013 14:57:48 -0700 Subject: [PATCH] drm/i915: Synchronize pread/pwrite with wait_rendering lifted from Daniel: pread/pwrite isn't about the object's domain at all, but purely about synchronizing for outstanding rendering. Replacing the call to set_to_gtt_domain with a wait_rendering would imo improve code readability. Furthermore we could pimp pread to only block for outstanding writes and not for reads. Since you're not the first one to trip over this: Can I volunteer you for a follow-up patch to fix this? v2: Switch the pwrite patch to use \!read_only. This was a typo in the original code. (Chris, Daniel) Recommended-by: Daniel Vetter Signed-off-by: Ben Widawsky [danvet: Fix up the logic fumble - wait_rendering has a bool readonly paramater, set_to_gtt_domain otoh has bool write. Breakage reported by Jani Nikula, I've double-checked that igt/gem_concurrent_blt/prw-* would have caught this.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gem.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index face1451786a..d00d24f7a976 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -41,6 +41,9 @@ static void i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *o static void i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj, bool force); static __must_check int +i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj, + bool readonly); +static __must_check int i915_gem_object_bind_to_vm(struct drm_i915_gem_object *obj, struct i915_address_space *vm, unsigned alignment, @@ -430,11 +433,9 @@ i915_gem_shmem_pread(struct drm_device *dev, * optimizes for the case when the gpu will dirty the data * anyway again before the next pread happens. */ needs_clflush = !cpu_cache_is_coherent(dev, obj->cache_level); - if (i915_gem_obj_bound_any(obj)) { - ret = i915_gem_object_set_to_gtt_domain(obj, false); - if (ret) - return ret; - } + ret = i915_gem_object_wait_rendering(obj, true); + if (ret) + return ret; } ret = i915_gem_object_get_pages(obj); @@ -746,11 +747,9 @@ i915_gem_shmem_pwrite(struct drm_device *dev, * optimizes for the case when the gpu will use the data * right away and we therefore have to clflush anyway. */ needs_clflush_after = cpu_write_needs_clflush(obj); - if (i915_gem_obj_bound_any(obj)) { - ret = i915_gem_object_set_to_gtt_domain(obj, true); - if (ret) - return ret; - } + ret = i915_gem_object_wait_rendering(obj, false); + if (ret) + return ret; } /* Same trick applies to invalidate partially written cachelines read * before writing. */ -- 2.20.1