drm/i915: report all active objects as busy

Incorporates a similar patch by Daniel Vetter, the alteration being to
report the current busy state after retiring.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 26 insertions, 14 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index fc61542cce8a..24ee4622484f 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4365,22 +4365,34 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
         }
 
         mutex_lock(&dev->struct_mutex);
-        /* Update the active list for the hardware's current position.
-         * Otherwise this only updates on a delayed timer or when irqs are
-         * actually unmasked, and our working set ends up being larger than
-         * required.
-         */
-        i915_gem_retire_requests(dev);
 
-        obj_priv = to_intel_bo(obj);
-        /* Don't count being on the flushing list against the object being
-         * done.  Otherwise, a buffer left on the flushing list but not getting
-         * flushed (because nobody's flushing that domain) won't ever return
-         * unbusy and get reused by libdrm's bo cache.  The other expected
-         * consumer of this interface, OpenGL's occlusion queries, also specs
-         * that the objects get unbusy "eventually" without any interference.
+        /* Count all active objects as busy, even if they are currently not used
+         * by the gpu. Users of this interface expect objects to eventually
+         * become non-busy without any further actions, therefore emit any
+         * necessary flushes here.
          */
-        args->busy = obj_priv->active && obj_priv->last_rendering_seqno != 0;
+        obj_priv = to_intel_bo(obj);
+        args->busy = obj_priv->active;
+        if (args->busy) {
+                /* Unconditionally flush objects, even when the gpu still uses this
+                 * object. Userspace calling this function indicates that it wants to
+                 * use this buffer rather sooner than later, so issuing the required
+                 * flush earlier is beneficial.
+                 */
+                if (obj->write_domain) {
+                        i915_gem_flush(dev, 0, obj->write_domain);
+                        (void)i915_add_request(dev, file_priv, obj->write_domain, obj_priv->ring);
+                }
+
+                /* Update the active list for the hardware's current position.
+                 * Otherwise this only updates on a delayed timer or when irqs
+                 * are actually unmasked, and our working set ends up being
+                 * larger than required.
+                 */
+                i915_gem_retire_requests_ring(dev, obj_priv->ring);
+
+                args->busy = obj_priv->active;
+        }
 
         drm_gem_object_unreference(obj);
         mutex_unlock(&dev->struct_mutex);