diff options
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem.c | 44 |
1 files changed, 38 insertions, 6 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 8ce363aa492c..b1c27da559e3 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1181,6 +1181,29 @@ static bool missed_irq(struct drm_i915_private *dev_priv, return test_bit(ring->id, &dev_priv->gpu_error.missed_irq_rings); } +static int __i915_spin_request(struct drm_i915_gem_request *rq) +{ + unsigned long timeout; + + if (i915_gem_request_get_ring(rq)->irq_refcount) + return -EBUSY; + + timeout = jiffies + 1; + while (!need_resched()) { + if (i915_gem_request_completed(rq, true)) + return 0; + + if (time_after_eq(jiffies, timeout)) + break; + + cpu_relax_lowlatency(); + } + if (i915_gem_request_completed(rq, false)) + return 0; + + return -EAGAIN; +} + /** * __i915_wait_request - wait until execution of request has finished * @req: duh! @@ -1225,12 +1248,20 @@ int __i915_wait_request(struct drm_i915_gem_request *req, if (INTEL_INFO(dev)->gen >= 6) gen6_rps_boost(dev_priv, file_priv); - if (!irq_test_in_progress && WARN_ON(!ring->irq_get(ring))) - return -ENODEV; - /* Record current time in case interrupted by signal, or wedged */ trace_i915_gem_request_wait_begin(req); before = ktime_get_raw_ns(); + + /* Optimistic spin for the next jiffie before touching IRQs */ + ret = __i915_spin_request(req); + if (ret == 0) + goto out; + + if (!irq_test_in_progress && WARN_ON(!ring->irq_get(ring))) { + ret = -ENODEV; + goto out; + } + for (;;) { struct timer_list timer; @@ -1279,14 +1310,15 @@ int __i915_wait_request(struct drm_i915_gem_request *req, destroy_timer_on_stack(&timer); } } - now = ktime_get_raw_ns(); - trace_i915_gem_request_wait_end(req); - if (!irq_test_in_progress) ring->irq_put(ring); finish_wait(&ring->irq_queue, &wait); +out: + now = ktime_get_raw_ns(); + trace_i915_gem_request_wait_end(req); + if (timeout) { s64 tres = *timeout - (now - before); |