From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 1 Mar 2018 10:33:38 +0000
Subject: drm/i915: Replace open-coded wait-for loop
Git-commit: ffed7bd23641b1a724f7fa49aa3781aa0ccbd9a0
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
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
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/i915/i915_gem.c | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3429,25 +3429,22 @@ i915_gem_idle_work_handler(struct work_s
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.
+ * 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).
*/
- 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));
+ __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);