Instead of synchronously cancelling the timer and re-enabling it inside
the reset callbacks, keep the timer enabled and let it die on its next
wakeup if no longer required. This allows
intel_engine_reset_breadcrumbs() to be used from an atomic
(timer/softirq) context such as required for resetting an engine.
It also allows us to react better to the user poking around debugfs for
testing missed irqs.
Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursu...@intel.com>
Cc: Mika Kuoppala <mika.kuopp...@linux.intel.com>
---
drivers/gpu/drm/i915/intel_breadcrumbs.c | 27 +++++++++++++++++++--------
1 file changed, 19 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_breadcrumbs.c
b/drivers/gpu/drm/i915/intel_breadcrumbs.c
index 671a6d61e29d..0a2128c6b418 100644
--- a/drivers/gpu/drm/i915/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c
@@ -130,11 +130,12 @@ static void intel_breadcrumbs_hangcheck(struct timer_list
*t)
static void intel_breadcrumbs_fake_irq(struct timer_list *t)
{
- struct intel_engine_cs *engine = from_timer(engine, t,
- breadcrumbs.fake_irq);
+ struct intel_engine_cs *engine =
+ from_timer(engine, t, breadcrumbs.fake_irq);
struct intel_breadcrumbs *b = &engine->breadcrumbs;
- /* The timer persists in case we cannot enable interrupts,
+ /*
+ * The timer persists in case we cannot enable interrupts,
* or if we have previously seen seqno/interrupt incoherency
* ("missed interrupt" syndrome, better known as a "missed breadcrumb").
* Here the worker will wake up every jiffie in order to kick the
@@ -148,6 +149,12 @@ static void intel_breadcrumbs_fake_irq(struct timer_list
*t)
if (!b->irq_armed)
return;
+ /* If the user has disabled the fake-irq, restore the hangchecking */
+ if (!test_bit(engine->id, &engine->i915->gpu_error.missed_irq_rings)) {
+ mod_timer(&b->hangcheck, wait_timeout());
+ return;
+ }
+
mod_timer(&b->fake_irq, jiffies + 1);
}
@@ -840,15 +847,22 @@ void intel_engine_reset_breadcrumbs(struct
intel_engine_cs *engine)
{
struct intel_breadcrumbs *b = &engine->breadcrumbs;
- cancel_fake_irq(engine);
spin_lock_irq(&b->irq_lock);
+ /*
+ * Leave the fake_irq timer enabled (if it is running), but clear the
+ * bit so that it turns itself off on its next wake up and goes back
+ * to the long hangcheck interval if still required.
+ */
+ clear_bit(engine->id, &engine->i915->gpu_error.missed_irq_rings);
+
if (b->irq_enabled)
irq_enable(engine);
else
irq_disable(engine);
- /* We set the IRQ_BREADCRUMB bit when we enable the irq presuming the
+ /*
+ * We set the IRQ_BREADCRUMB bit when we enable the irq presuming the
* GPU is active and may have already executed the MI_USER_INTERRUPT
* before the CPU is ready to receive. However, the engine is currently
* idle (we haven't started it yet), there is no possibility for a
@@ -857,9 +871,6 @@ void intel_engine_reset_breadcrumbs(struct intel_engine_cs
*engine)
*/
clear_bit(ENGINE_IRQ_BREADCRUMB, &engine->irq_posted);
- if (b->irq_armed)
- enable_fake_irq(b);
-
spin_unlock_irq(&b->irq_lock);
}
--
2.16.3
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