From e5facdf9644f4490520e0489a0252e8feaba3744 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 23 Dec 2016 14:57:57 +0000 Subject: [PATCH] drm/i915: Don't clflush before release phys object MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When we teardown the backing storage for the phys object, we copy from the coherent contiguous block back to the shmemfs object, clflushing as we go. Trying to clflush the invalid sg beforehand just oops and would be redundant (due to it already being coherent, and clflushed afterwards). Reported-by: Ville Syrjälä Signed-off-by: Chris Wilson Cc: Joonas Lahtinen Cc: Reviewed-by: Joonas Lahtinen Link: http://patchwork.freedesktop.org/patch/msgid/20161223145804.6605-3-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 0f5f29c7ce40..82fc4d4c665e 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -246,14 +246,16 @@ err_phys: static void __i915_gem_object_release_shmem(struct drm_i915_gem_object *obj, - struct sg_table *pages) + struct sg_table *pages, + bool needs_clflush) { GEM_BUG_ON(obj->mm.madv == __I915_MADV_PURGED); if (obj->mm.madv == I915_MADV_DONTNEED) obj->mm.dirty = false; - if ((obj->base.read_domains & I915_GEM_DOMAIN_CPU) == 0 && + if (needs_clflush && + (obj->base.read_domains & I915_GEM_DOMAIN_CPU) == 0 && !cpu_cache_is_coherent(obj->base.dev, obj->cache_level)) drm_clflush_sg(pages); @@ -265,7 +267,7 @@ static void i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj, struct sg_table *pages) { - __i915_gem_object_release_shmem(obj, pages); + __i915_gem_object_release_shmem(obj, pages, false); if (obj->mm.dirty) { struct address_space *mapping = obj->base.filp->f_mapping; @@ -2233,7 +2235,7 @@ i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj, struct sgt_iter sgt_iter; struct page *page; - __i915_gem_object_release_shmem(obj, pages); + __i915_gem_object_release_shmem(obj, pages, true); i915_gem_gtt_finish_pages(obj, pages); -- 2.20.1