If a worker requeues itself, it may switch to a different kworker pool, which flush_work() considers as complete. To be strict, we then need to keep flushing the work until it is no longer pending. References: https://bugs.freedesktop.org/show_bug.cgi?id=102456 Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxx> --- drivers/gpu/drm/i915/i915_debugfs.c | 3 +-- drivers/gpu/drm/i915/i915_gem.c | 3 +-- drivers/gpu/drm/i915/i915_utils.h | 13 +++++++++++++ 3 files changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 48572b157222..1dd687a74879 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -4202,8 +4202,7 @@ fault_irq_set(struct drm_i915_private *i915, mutex_unlock(&i915->drm.struct_mutex); /* Flush idle worker to disarm irq */ - while (flush_delayed_work(&i915->gt.idle_work)) - ; + drain_delayed_work(&i915->gt.idle_work); return 0; diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index e4cc08bc518c..1829d3fa15d1 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -4582,8 +4582,7 @@ int i915_gem_suspend(struct drm_i915_private *dev_priv) /* As the idle_work is rearming if it detects a race, play safe and * repeat the flush until it is definitely idle. */ - while (flush_delayed_work(&dev_priv->gt.idle_work)) - ; + drain_delayed_work(&dev_priv->gt.idle_work); /* Assert that we sucessfully flushed all the work and * reset the GPU back to its idle, low power state. diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h index 12fc250b47b9..4f7ffa0976b1 100644 --- a/drivers/gpu/drm/i915/i915_utils.h +++ b/drivers/gpu/drm/i915/i915_utils.h @@ -119,4 +119,17 @@ static inline void __list_del_many(struct list_head *head, WRITE_ONCE(head->next, first); } +/* + * Wait until the work is finally complete, even if it tries to postpone + * by requeueing itself. Note, that if the worker never cancels itself, + * we will spin forever. + */ +static inline void drain_delayed_work(struct delayed_work *dw) +{ + do { + while (flush_delayed_work(dw)) + ; + } while (delayed_work_pending(dw)); +} + #endif /* !__I915_UTILS_H */ -- 2.14.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
