drm/i915/gtt: Unmap the PCI pages after unbinding them from the GTT

Dave Airlie spotted that his ILK laptop with DMAR enabled was generating
the occasional DMAR warning.

"The ordering in the previous code was to rewrite the GTT table before
unmapping the pages and that makes sense to me."

This is his stable patch ported to d-i-n.

Reported-by: Dave Airlie <airlied@redhat.com>
Original-patch-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 86673e77d7cb51c9ec92dd89a2ee177224dd2fc8..70433ae50ac80fe4fe44f90be74c4cb5840c3715 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -85,15 +85,11 @@ int i915_gem_gtt_bind_object(struct drm_i915_gem_object *obj)
 
 void i915_gem_gtt_unbind_object(struct drm_i915_gem_object *obj)
 {
-       struct drm_device *dev = obj->base.dev;
-       struct drm_i915_private *dev_priv = dev->dev_private;
+       intel_gtt_clear_range(obj->gtt_space->start >> PAGE_SHIFT,
+                             obj->base.size >> PAGE_SHIFT);
 
-       if (dev_priv->mm.gtt->needs_dmar) {
+       if (obj->sg_list) {
                intel_gtt_unmap_memory(obj->sg_list, obj->num_sg);
                obj->sg_list = NULL;
-               obj->num_sg = 0;
        }
-
-       intel_gtt_clear_range(obj->gtt_space->start >> PAGE_SHIFT,
-                             obj->base.size >> PAGE_SHIFT);
 }