[Intel-gfx] [PATCH] drm/i915: Replace open-coded evict everything in i915_gem_idle()

[Chris Wilson]

With the introduction of the hang-check, we can safely expect that
i915_wait_request() will always return even when the GPU hangs, and so
do not need to open code the wait in order to manually check for the hang.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem.c |  110 ++++----------------------------------
 1 files changed, 12 insertions(+), 98 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 21950ef..2324605 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4403,114 +4403,28 @@ i915_gem_idle(struct drm_device *dev)
 		return 0;
 	}
 
+	ret = i915_gem_evict_everything(dev);
+	if (ret) {
+		mutex_unlock(&dev->struct_mutex);
+		return ret;
+	}
+
 	/* Hack!  Don't let anybody do execbuf while we don't control the chip.
 	 * We need to replace this with a semaphore, or something.
+	 * And not confound mm.suspended!
 	 */
 	dev_priv->mm.suspended = 1;
 	del_timer(&dev_priv->hangcheck_timer);
 
-	/* Cancel the retire work handler, wait for it to finish if running
-	 */
-	mutex_unlock(&dev->struct_mutex);
-	cancel_delayed_work_sync(&dev_priv->mm.retire_work);
-	mutex_lock(&dev->struct_mutex);
-
 	i915_kernel_lost_context(dev);
+	i915_gem_cleanup_ringbuffer(dev);
 
-	/* Flush the GPU along with all non-CPU write domains
-	 */
-	i915_gem_flush(dev, I915_GEM_GPU_DOMAINS, I915_GEM_GPU_DOMAINS);
-	seqno = i915_add_request(dev, NULL, I915_GEM_GPU_DOMAINS);
-
-	if (seqno == 0) {
-		mutex_unlock(&dev->struct_mutex);
-		return -ENOMEM;
-	}
-
-	dev_priv->mm.waiting_gem_seqno = seqno;
-	last_seqno = 0;
-	stuck = 0;
-	for (;;) {
-		cur_seqno = i915_get_gem_seqno(dev);
-		if (i915_seqno_passed(cur_seqno, seqno))
-			break;
-		if (last_seqno == cur_seqno) {
-			if (stuck++ > 100) {
-				DRM_ERROR("hardware wedged\n");
-				atomic_set(&dev_priv->mm.wedged, 1);
-				DRM_WAKEUP(&dev_priv->irq_queue);
-				break;
-			}
-		}
-		msleep(10);
-		last_seqno = cur_seqno;
-	}
-	dev_priv->mm.waiting_gem_seqno = 0;
-
-	i915_gem_retire_requests(dev);
-
-	spin_lock(&dev_priv->mm.active_list_lock);
-	if (!atomic_read(&dev_priv->mm.wedged)) {
-		/* Active and flushing should now be empty as we've
-		 * waited for a sequence higher than any pending execbuffer
-		 */
-		WARN_ON(!list_empty(&dev_priv->mm.active_list));
-		WARN_ON(!list_empty(&dev_priv->mm.flushing_list));
-		/* Request should now be empty as we've also waited
-		 * for the last request in the list
-		 */
-		WARN_ON(!list_empty(&dev_priv->mm.request_list));
-	}
+	mutex_unlock(&dev->struct_mutex);
 
-	/* Empty the active and flushing lists to inactive.  If there's
-	 * anything left at this point, it means that we're wedged and
-	 * nothing good's going to happen by leaving them there.  So strip
-	 * the GPU domains and just stuff them onto inactive.
+	/* Cancel the retire work handler, which should be idle now after
+	 * evicting everything.
 	 */
-	while (!list_empty(&dev_priv->mm.active_list)) {
-		struct drm_gem_object *obj;
-		uint32_t old_write_domain;
-
-		obj = list_first_entry(&dev_priv->mm.active_list,
-				       struct drm_i915_gem_object,
-				       list)->obj;
-		old_write_domain = obj->write_domain;
-		obj->write_domain &= ~I915_GEM_GPU_DOMAINS;
-		i915_gem_object_move_to_inactive(obj);
-
-		trace_i915_gem_object_change_domain(obj,
-						    obj->read_domains,
-						    old_write_domain);
-	}
-	spin_unlock(&dev_priv->mm.active_list_lock);
-
-	while (!list_empty(&dev_priv->mm.flushing_list)) {
-		struct drm_gem_object *obj;
-		uint32_t old_write_domain;
-
-		obj = list_first_entry(&dev_priv->mm.flushing_list,
-				       struct drm_i915_gem_object,
-				       list)->obj;
-		old_write_domain = obj->write_domain;
-		obj->write_domain &= ~I915_GEM_GPU_DOMAINS;
-		i915_gem_object_move_to_inactive(obj);
-
-		trace_i915_gem_object_change_domain(obj,
-						    obj->read_domains,
-						    old_write_domain);
-	}
-
-
-	/* Move all inactive buffers out of the GTT. */
-	ret = i915_gem_evict_from_inactive_list(dev);
-	WARN_ON(!list_empty(&dev_priv->mm.inactive_list));
-	if (ret) {
-		mutex_unlock(&dev->struct_mutex);
-		return ret;
-	}
-
-	i915_gem_cleanup_ringbuffer(dev);
-	mutex_unlock(&dev->struct_mutex);
+	cancel_delayed_work_sync(&dev_priv->mm.retire_work);
 
 	return 0;
 }
-- 
1.6.6