drm/i915: Reduce hangcheck frequency

By reducing the hangcheck frequency we check less often, conserving
resources, and still detect a lock up quickly. On a fast machine with a
slow GPU (like a Core2 paired with a 945G) it is easy for the hangcheck to
misfire as we check too fast.

Also once hung and if we fail to completely reset the chip, we have a
nasty habit of proclaming a hang many times a second and generating a
strobe-like display.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

3 files changed, 11 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 232555e33929..70cbe3cee1ab 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -299,7 +299,7 @@ typedef struct drm_i915_private {
         int num_pipe;
 
         /* For hangcheck timer */
-#define DRM_I915_HANGCHECK_PERIOD 75 /* in jiffies */
+#define DRM_I915_HANGCHECK_PERIOD 250 /* in ms */
         struct timer_list hangcheck_timer;
         int hangcheck_count;
         uint32_t last_acthd;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e0b7ddc917c2..9391765af70d 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1639,9 +1639,11 @@ i915_add_request(struct drm_device *dev,
         }
 
         if (!dev_priv->mm.suspended) {
-                mod_timer(&dev_priv->hangcheck_timer, jiffies + DRM_I915_HANGCHECK_PERIOD);
+                mod_timer(&dev_priv->hangcheck_timer,
+                          jiffies + msecs_to_jiffies(DRM_I915_HANGCHECK_PERIOD));
                 if (was_empty)
-                        queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, HZ);
+                        queue_delayed_work(dev_priv->wq,
+                                           &dev_priv->mm.retire_work, HZ);
         }
         return seqno;
 }
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index bc8438d6d843..e64b8eaa0b9d 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -328,7 +328,8 @@ static irqreturn_t ironlake_irq_handler(struct drm_device *dev)
                 trace_i915_gem_request_complete(dev, seqno);
                 DRM_WAKEUP(&dev_priv->render_ring.irq_queue);
                 dev_priv->hangcheck_count = 0;
-                mod_timer(&dev_priv->hangcheck_timer, jiffies + DRM_I915_HANGCHECK_PERIOD);
+                mod_timer(&dev_priv->hangcheck_timer,
+                          jiffies + msecs_to_jiffies(DRM_I915_HANGCHECK_PERIOD));
         }
         if (gt_iir & GT_BSD_USER_INTERRUPT)
                 DRM_WAKEUP(&dev_priv->bsd_ring.irq_queue);
@@ -1018,7 +1019,8 @@ irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
                         trace_i915_gem_request_complete(dev, seqno);
                         DRM_WAKEUP(&dev_priv->render_ring.irq_queue);
                         dev_priv->hangcheck_count = 0;
-                        mod_timer(&dev_priv->hangcheck_timer, jiffies + DRM_I915_HANGCHECK_PERIOD);
+                        mod_timer(&dev_priv->hangcheck_timer,
+                                  jiffies + msecs_to_jiffies(DRM_I915_HANGCHECK_PERIOD));
                 }
 
                 if (HAS_BSD(dev) && (iir & I915_BSD_USER_INTERRUPT))
@@ -1394,7 +1396,8 @@ void i915_hangcheck_elapsed(unsigned long data)
 
 out:
         /* Reset timer case chip hangs without another request being added */
-        mod_timer(&dev_priv->hangcheck_timer, jiffies + DRM_I915_HANGCHECK_PERIOD);
+        mod_timer(&dev_priv->hangcheck_timer,
+                  jiffies + msecs_to_jiffies(DRM_I915_HANGCHECK_PERIOD));
 }
 
 /* drm_dma.h hooks