drm/i915: Drop ORIGIN_GTT for untracked GTT writes
If FBC is set on a framebuffer that is unmapped, all GTT faults will be
from a partial mapping. Writes by the user through the partial VMA are
then untracked by the FBC and so we must use the ORIGIN_CPU when flushing
the I915_GEM_DOMAIN_GTT.
v2: Keep ORIGIN_CPU for set-to-domain(.write=CPU)
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: "Zanoni, Paulo R" <paulo.r.zanoni@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160818161718.27187-25-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e4c18c7..9811980 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1497,8 +1497,8 @@
static inline enum fb_op_origin
write_origin(struct drm_i915_gem_object *obj, unsigned domain)
{
- return domain == I915_GEM_DOMAIN_GTT && !obj->has_wc_mmap ?
- ORIGIN_GTT : ORIGIN_CPU;
+ return (domain == I915_GEM_DOMAIN_GTT ?
+ obj->frontbuffer_ggtt_origin : ORIGIN_CPU);
}
/**
@@ -1658,7 +1658,7 @@
up_write(&mm->mmap_sem);
/* This may race, but that's ok, it only gets set */
- WRITE_ONCE(obj->has_wc_mmap, true);
+ WRITE_ONCE(obj->frontbuffer_ggtt_origin, ORIGIN_CPU);
}
i915_gem_object_put_unlocked(obj);
if (IS_ERR((void *)addr))
@@ -1761,6 +1761,11 @@
if (chunk_size >= obj->base.size >> PAGE_SHIFT)
view.type = I915_GGTT_VIEW_NORMAL;
+ /* Userspace is now writing through an untracked VMA, abandon
+ * all hope that the hardware is able to track future writes.
+ */
+ obj->frontbuffer_ggtt_origin = ORIGIN_CPU;
+
vma = i915_gem_object_ggtt_pin(obj, &view, 0, 0, PIN_MAPPABLE);
}
if (IS_ERR(vma)) {
@@ -4093,6 +4098,7 @@
obj->ops = ops;
+ obj->frontbuffer_ggtt_origin = ORIGIN_GTT;
obj->madv = I915_MADV_WILLNEED;
i915_gem_info_add_obj(to_i915(obj->base.dev), obj->base.size);
