From 681c774d349018c0f47a770133b952f50328d957 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 9 Jul 2019 09:17:18 +0100 Subject: [PATCH] drm/i915/userptr: Don't mark readonly objects as dirty If we map an object as readonly into the GTT, we know that the GPU cannot have written to it and so the object is not dirty and we don't need to flush the writes back to the system. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20190709081718.27843-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index 32d208e..b9d2bb1 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -663,6 +663,14 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj, __i915_gem_object_release_shmem(obj, pages, true); i915_gem_gtt_finish_pages(obj, pages); + /* + * We always mark objects as dirty when they are used by the GPU, + * just in case. However, if we set the vma as being read-only we know + * that the object will never have been written to. + */ + if (i915_gem_object_is_readonly(obj)) + obj->mm.dirty = false; + for_each_sgt_page(page, sgt_iter, pages) { if (obj->mm.dirty) /* -- 2.7.4