drm/i915: Replace open-coded wait-for loop (ffed7bd2) · Commits · 戴 / test

Now that we can pass arbitrary commands into the base __wait_for() macro, we can reimplement the open-coded wait-for inside i915_gem_idle_work_handler() using the new macro. This means that instead of using ktime, we now use jiffies, and benefit from the exponential sleep backoff that allows a fast response if the HW settles quickly. Signed-off-by:

Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reviewed-by:

Mika Kuoppala <mika.kuoppala@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180301103338.5380-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_gem.c

+9 −12

Original line number	Diff line number	Diff line
		@@ -3417,25 +3417,22 @@ i915_gem_idle_work_handler(struct work_struct *work)
		container_of(work, typeof(*dev_priv), gt.idle_work.work);
		unsigned int epoch = I915_EPOCH_INVALID;
		bool rearm_hangcheck;
		ktime_t end;

		if (!READ_ONCE(dev_priv->gt.awake))
		return;

		/*
		* Wait for last execlists context complete, but bail out in case a
		* new request is submitted.
		*/
		end = ktime_add_ms(ktime_get(), I915_IDLE_ENGINES_TIMEOUT);
		do {
		if (new_requests_since_last_retire(dev_priv))
		return;

		if (intel_engines_are_idle(dev_priv))
		break;

		usleep_range(100, 500);
		} while (ktime_before(ktime_get(), end));
		* new request is submitted. As we don't trust the hardware, we
		* continue on if the wait times out. This is necessary to allow
		* the machine to suspend even if the hardware dies, and we will
		* try to recover in resume (after depriving the hardware of power,
		* it may be in a better mmod).
		*/
		__wait_for(if (new_requests_since_last_retire(dev_priv)) return,
		intel_engines_are_idle(dev_priv),
		I915_IDLE_ENGINES_TIMEOUT * 1000,
		10, 500);

		rearm_hangcheck =
		cancel_delayed_work_sync(&dev_priv->gpu_error.hangcheck_work);

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