drm/i915: Avoid tainting i915_gem_park() with wakeref.lock (dfdeaff2) · Commits · 戴 / test

While we need to flush the wakeref before parking, we do not need to perform the i915_gem_park() itself underneath the wakeref lock, merely the struct_mutex. If we rearrange the locks, we can avoid the unnecessary tainting. Signed-off-by:

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

Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190614220616.24932-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gem/i915_gem_pm.c

+8 −9

Original line number	Diff line number	Diff line
		@@ -48,23 +48,22 @@ static void idle_work_handler(struct work_struct *work)
		{
		struct drm_i915_private *i915 =
		container_of(work, typeof(*i915), gem.idle_work);
		bool restart = true;
		bool park;

		cancel_delayed_work(&i915->gem.retire_work);
		cancel_delayed_work_sync(&i915->gem.retire_work);
		mutex_lock(&i915->drm.struct_mutex);

		intel_wakeref_lock(&i915->gt.wakeref);
		if (!intel_wakeref_active(&i915->gt.wakeref) && !work_pending(work)) {
		i915_gem_park(i915);
		restart = false;
		}
		park = !intel_wakeref_active(&i915->gt.wakeref) && !work_pending(work);
		intel_wakeref_unlock(&i915->gt.wakeref);

		mutex_unlock(&i915->drm.struct_mutex);
		if (restart)
		if (park)
		i915_gem_park(i915);
		else
		queue_delayed_work(i915->wq,
		&i915->gem.retire_work,
		round_jiffies_up_relative(HZ));

		mutex_unlock(&i915->drm.struct_mutex);
		}

		static void retire_work_handler(struct work_struct *work)

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