[intel-gem] Use polling in i915_gem_idle instead of interrupts.

While waiting for the hardware to idle on leavevt or lastclose, poll
for the sync sequence number instead of waiting for an interrupt. This
allows the code to bail if the hardware hangs for some reason. Also, this
avoids issues with signals as the exisiting wait function is interruptible.

diff --git a/linux-core/i915_gem.c b/linux-core/i915_gem.c
index e086bc1..27b6ddb 100644 (file)
--- a/linux-core/i915_gem.c
+++ b/linux-core/i915_gem.c
@@ -2139,8 +2139,9 @@ static int
 i915_gem_idle(struct drm_device *dev)
 {
        drm_i915_private_t *dev_priv = dev->dev_private;
-       uint32_t seqno;
+       uint32_t seqno, cur_seqno, last_seqno;
        int ret;
+       int stuck;
 
        if (dev_priv->mm.suspended)
                return 0;
@@ -2161,11 +2162,26 @@ i915_gem_idle(struct drm_device *dev)
                mutex_unlock(&dev->struct_mutex);
                return -ENOMEM;
        }
-       ret = i915_wait_request(dev, seqno);
-       if (ret) {
-               mutex_unlock(&dev->struct_mutex);
-               return ret;
+
+       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");
+                               break;
+                       }
+               }
+               msleep(10);
+               last_seqno = cur_seqno;
        }
+       dev_priv->mm.waiting_gem_seqno = 0;
+
+       i915_gem_retire_requests(dev);
 
        /* Active and flushing should now be empty as we've
         * waited for a sequence higher than any pending execbuffer
@@ -2521,14 +2537,17 @@ void
 i915_gem_lastclose(struct drm_device *dev)
 {
        int ret;
+       drm_i915_private_t *dev_priv = dev->dev_private;
 
        mutex_lock(&dev->struct_mutex);
 
-       ret = i915_gem_idle(dev);
-       if (ret)
-               DRM_ERROR("failed to idle hardware: %d\n", ret);
-
-       i915_gem_cleanup_ringbuffer(dev);
+       if (dev_priv->ring.ring_obj != NULL) {
+               ret = i915_gem_idle(dev);
+               if (ret)
+                       DRM_ERROR("failed to idle hardware: %d\n", ret);
+       
+               i915_gem_cleanup_ringbuffer(dev);
+       }
        
        mutex_unlock(&dev->struct_mutex);
 }