drm/i915: Include instdone[1] in hangcheck

References:

  Bug 26691 - Spurious hangcheck whilst executing a long shader over a
              large vertex buffer
  https://bugs.freedesktop.org/show_bug.cgi?id=26691

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 23 insertions, 15 deletions

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index fb6b46285471..85785a8844ed 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1229,16 +1229,21 @@ void i915_hangcheck_elapsed(unsigned long data)
 {
         struct drm_device *dev = (struct drm_device *)data;
         drm_i915_private_t *dev_priv = dev->dev_private;
-        uint32_t acthd;
+        uint32_t acthd, instdone, instdone1;
 
         /* No reset support on this chip yet. */
         if (IS_GEN6(dev))
                 return;
 
-        if (!IS_I965G(dev))
+        if (!IS_I965G(dev)) {
                 acthd = I915_READ(ACTHD);
-        else
+                instdone = I915_READ(INSTDONE);
+                instdone1 = 0;
+        } else {
                 acthd = I915_READ(ACTHD_I965);
+                instdone = I915_READ(INSTDONE_I965);
+                instdone1 = I915_READ(INSTDONE1);
+        }
 
         /* If all work is done then ACTHD clearly hasn't advanced. */
         if (list_empty(&dev_priv->render_ring.request_list) ||
@@ -1249,21 +1254,24 @@ void i915_hangcheck_elapsed(unsigned long data)
                 return;
         }
 
-        if (dev_priv->last_acthd == acthd && dev_priv->hangcheck_count > 0) {
-                DRM_ERROR("Hangcheck timer elapsed... GPU hung\n");
-                i915_handle_error(dev, true);
-                return;
-        } 
+        if (dev_priv->last_acthd == acthd &&
+            dev_priv->last_instdone == instdone &&
+            dev_priv->last_instdone1 == instdone1) {
+                if (dev_priv->hangcheck_count++ > 1) {
+                        DRM_ERROR("Hangcheck timer elapsed... GPU hung\n");
+                        i915_handle_error(dev, true);
+                        return;
+                }
+        } else {
+                dev_priv->hangcheck_count = 0;
+
+                dev_priv->last_acthd = acthd;
+                dev_priv->last_instdone = instdone;
+                dev_priv->last_instdone1 = instdone1;
+        }
 
         /* Reset timer case chip hangs without another request being added */
         mod_timer(&dev_priv->hangcheck_timer, jiffies + DRM_I915_HANGCHECK_PERIOD);
-
-        if (acthd != dev_priv->last_acthd)
-                dev_priv->hangcheck_count = 0;
-        else
-                dev_priv->hangcheck_count++;
-
-        dev_priv->last_acthd = acthd;
 }
 
 /* drm_dma.h hooks