Merge branches 'pm-core', 'pm-qos', 'pm-domains' and 'pm-opp'

[linux.git] / drivers / gpu / drm / i915 / i915_gem.c

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index b3f1134fb9c8e44e8ac1cde69f076305cf430912..24b5b046754b37e8b8e3ab2c04a9f890b41eecf9 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2010,8 +2010,16 @@ void i915_gem_runtime_suspend(struct drm_i915_private *dev_priv)
        for (i = 0; i < dev_priv->num_fence_regs; i++) {
                struct drm_i915_fence_reg *reg = &dev_priv->fence_regs[i];
 
-               if (WARN_ON(reg->pin_count))
-                       continue;
+               /* Ideally we want to assert that the fence register is not
+                * live at this point (i.e. that no piece of code will be
+                * trying to write through fence + GTT, as that both violates
+                * our tracking of activity and associated locking/barriers,
+                * but also is illegal given that the hw is powered down).
+                *
+                * Previously we used reg->pin_count as a "liveness" indicator.
+                * That is not sufficient, and we need a more fine-grained
+                * tool if we want to have a sanity check here.
+                */
 
                if (!reg->vma)
                        continue;