drm/i915: track ring progression using seqnos

Instead of relying in acthd, track ring seqno progression
to detect if ring has hung.

v2: put hangcheck stuff inside struct (Chris Wilson)

v3: initialize hangcheck.seqno (Ben Widawsky)

Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

4 files changed, 20 insertions, 19 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e09c54c73a22..e417049ea581 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -842,8 +842,6 @@ struct i915_gpu_error {
 #define DRM_I915_HANGCHECK_JIFFIES msecs_to_jiffies(DRM_I915_HANGCHECK_PERIOD)
         struct timer_list hangcheck_timer;
         int hangcheck_count;
-        uint32_t last_acthd[I915_NUM_RINGS];
-        uint32_t prev_instdone[I915_NUM_INSTDONE_REG];
 
         /* For reset and error_state handling. */
         spinlock_t lock;
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 0e5c9b0cc5a6..004ad3455992 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -2384,22 +2384,19 @@ 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[I915_NUM_RINGS], instdone[I915_NUM_INSTDONE_REG];
         struct intel_ring_buffer *ring;
         bool err = false, idle;
         int i;
+        u32 seqno[I915_NUM_RINGS];
+        bool work_done;
 
         if (!i915_enable_hangcheck)
                 return;
 
-        memset(acthd, 0, sizeof(acthd));
         idle = true;
         for_each_ring(ring, dev_priv, i) {
-                u32 seqno;
-
-                seqno = ring->get_seqno(ring, false);
-                idle &= i915_hangcheck_ring_idle(ring, seqno, &err);
-            acthd[i] = intel_ring_get_active_head(ring);
+                seqno[i] = ring->get_seqno(ring, false);
+                idle &= i915_hangcheck_ring_idle(ring, seqno[i], &err);
         }
 
         /* If all work is done then ACTHD clearly hasn't advanced. */
@@ -2415,20 +2412,19 @@ void i915_hangcheck_elapsed(unsigned long data)
                 return;
         }
 
-        i915_get_extra_instdone(dev, instdone);
-        if (memcmp(dev_priv->gpu_error.last_acthd, acthd,
-                   sizeof(acthd)) == 0 &&
-            memcmp(dev_priv->gpu_error.prev_instdone, instdone,
-                   sizeof(instdone)) == 0) {
+        work_done = false;
+        for_each_ring(ring, dev_priv, i) {
+                if (ring->hangcheck.seqno != seqno[i]) {
+                        work_done = true;
+                        ring->hangcheck.seqno = seqno[i];
+                }
+        }
+
+        if (!work_done) {
                 if (i915_hangcheck_hung(dev))
                         return;
         } else {
                 dev_priv->gpu_error.hangcheck_count = 0;
-
-                memcpy(dev_priv->gpu_error.last_acthd, acthd,
-                       sizeof(acthd));
-                memcpy(dev_priv->gpu_error.prev_instdone, instdone,
-                       sizeof(instdone));
         }
 
 repeat:
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 3d2c236e15ab..5698faeee6f6 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1502,6 +1502,7 @@ void intel_ring_init_seqno(struct intel_ring_buffer *ring, u32 seqno)
         }
 
         ring->set_seqno(ring, seqno);
+        ring->hangcheck.seqno = seqno;
 }
 
 void intel_ring_advance(struct intel_ring_buffer *ring)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index dac1614a1bca..ef374a892105 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -37,6 +37,10 @@ struct  intel_hw_status_page {
 #define I915_READ_SYNC_0(ring) I915_READ(RING_SYNC_0((ring)->mmio_base))
 #define I915_READ_SYNC_1(ring) I915_READ(RING_SYNC_1((ring)->mmio_base))
 
+struct intel_ring_hangcheck {
+        u32 seqno;
+};
+
 struct  intel_ring_buffer {
         const char      *name;
         enum intel_ring_id {
@@ -137,6 +141,8 @@ struct  intel_ring_buffer {
         struct i915_hw_context *default_context;
         struct i915_hw_context *last_context;
 
+        struct intel_ring_hangcheck hangcheck;
+
         void *private;
 };