[Intel-gfx] [PATCH] drm/i915: Fix __wait_seqno to use true infinite timeouts
Chris Wilson
chris at chris-wilson.co.uk
Fri Aug 23 03:05:16 CEST 2013
Rather than continue to fix up the timeouts to work around the interface
impedence in wait_event_*(), open code the combination of
wait_event[_interruptible][_timeout]. And note the code size reduction,
and dare say readability?, in doing so..
v2: In order to satisfy the debug requirement of logging missed
interrupts with the real world requirments of making machines work even
if interrupts are hosed, we revert to polling after detecting a missed
interrupt.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_drv.h | 1 +
drivers/gpu/drm/i915/i915_gem.c | 103 ++++++++++++++++++++++------------------
drivers/gpu/drm/i915/i915_irq.c | 8 ++--
3 files changed, 63 insertions(+), 49 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 321159f..ad298f4 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -658,6 +658,7 @@ enum intel_sbi_destination {
#define QUIRK_LVDS_SSC_DISABLE (1<<1)
#define QUIRK_INVERT_BRIGHTNESS (1<<2)
#define QUIRK_NO_PCH_PWM_ENABLE (1<<3)
+#define QUIRK_MISSED_SEQNO_INTERRUPTS (1<<4)
struct intel_fbdev;
struct intel_fbc_work;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 4f1ca12..b265def 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1067,6 +1067,11 @@ i915_gem_check_olr(struct intel_ring_buffer *ring, u32 seqno)
return ret;
}
+static void fake_irq(unsigned long data)
+{
+ wake_up((wait_queue_head_t *)data);
+}
+
/**
* __wait_seqno - wait until execution of seqno has finished
* @ring: the ring expected to report seqno
@@ -1090,10 +1095,9 @@ static int __wait_seqno(struct intel_ring_buffer *ring, u32 seqno,
bool interruptible, struct timespec *timeout)
{
drm_i915_private_t *dev_priv = ring->dev->dev_private;
- struct timespec before, now, wait_time={1,0};
- unsigned long timeout_jiffies;
- long end;
- bool wait_forever = true;
+ struct timespec before, now;
+ DEFINE_WAIT(wait);
+ long timeout_jiffies;
int ret;
WARN(dev_priv->pc8.irqs_disabled, "IRQs disabled\n");
@@ -1101,51 +1105,68 @@ static int __wait_seqno(struct intel_ring_buffer *ring, u32 seqno,
if (i915_seqno_passed(ring->get_seqno(ring, true), seqno))
return 0;
- trace_i915_gem_request_wait_begin(ring, seqno);
-
- if (timeout != NULL) {
- wait_time = *timeout;
- wait_forever = false;
- }
-
- timeout_jiffies = timespec_to_jiffies_timeout(&wait_time);
+ timeout_jiffies = timeout ? timespec_to_jiffies_timeout(timeout) : 0;
if (WARN_ON(!ring->irq_get(ring)))
return -ENODEV;
- /* Record current time in case interrupted by signal, or wedged * */
+ /* Record current time in case interrupted by signal, or wedged */
+ trace_i915_gem_request_wait_begin(ring, seqno);
getrawmonotonic(&before);
+ for (;;) {
+ struct timer_list timer;
-#define EXIT_COND \
- (i915_seqno_passed(ring->get_seqno(ring, false), seqno) || \
- i915_reset_in_progress(&dev_priv->gpu_error) || \
- reset_counter != atomic_read(&dev_priv->gpu_error.reset_counter))
- do {
- if (interruptible)
- end = wait_event_interruptible_timeout(ring->irq_queue,
- EXIT_COND,
- timeout_jiffies);
- else
- end = wait_event_timeout(ring->irq_queue, EXIT_COND,
- timeout_jiffies);
+ prepare_to_wait(&ring->irq_queue, &wait,
+ interruptible ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
/* We need to check whether any gpu reset happened in between
* the caller grabbing the seqno and now ... */
- if (reset_counter != atomic_read(&dev_priv->gpu_error.reset_counter))
- end = -EAGAIN;
+ if (reset_counter != atomic_read(&dev_priv->gpu_error.reset_counter)) {
+ /* ... but upgrade the -EGAIN to an -EIO if the gpu
+ * is truely gone. */
+ ret = i915_gem_check_wedge(&dev_priv->gpu_error, interruptible);
+ if (ret == 0)
+ ret = -EAGAIN;
+ break;
+ }
- /* ... but upgrade the -EGAIN to an -EIO if the gpu is truely
- * gone. */
- ret = i915_gem_check_wedge(&dev_priv->gpu_error, interruptible);
- if (ret)
- end = ret;
- } while (end == 0 && wait_forever);
+ if (i915_seqno_passed(ring->get_seqno(ring, false), seqno)) {
+ ret = 0;
+ break;
+ }
+ if (interruptible && signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+
+ timer.function = NULL;
+ if (dev_priv->quirks & QUIRK_MISSED_SEQNO_INTERRUPTS) {
+ setup_timer_on_stack(&timer, fake_irq, (unsigned long)&ring->irq_queue);
+ mod_timer(&timer, round_jiffies_up_relative(HZ/100));
+ }
+
+ if (timeout) {
+ if (timeout_jiffies == 0) {
+ ret = -ETIME;
+ break;
+ }
+
+ timeout_jiffies = schedule_timeout(timeout_jiffies);
+ } else
+ schedule();
+
+ if (timer.function) {
+ del_singleshot_timer_sync(&timer);
+ destroy_timer_on_stack(&timer);
+ }
+ }
getrawmonotonic(&now);
+ trace_i915_gem_request_wait_end(ring, seqno);
ring->irq_put(ring);
- trace_i915_gem_request_wait_end(ring, seqno);
-#undef EXIT_COND
+
+ finish_wait(&ring->irq_queue, &wait);
if (timeout) {
struct timespec sleep_time = timespec_sub(now, before);
@@ -1154,17 +1175,7 @@ static int __wait_seqno(struct intel_ring_buffer *ring, u32 seqno,
set_normalized_timespec(timeout, 0, 0);
}
- switch (end) {
- case -EIO:
- case -EAGAIN: /* Wedged */
- case -ERESTARTSYS: /* Signal */
- return (int)end;
- case 0: /* Timeout */
- return -ETIME;
- default: /* Completed */
- WARN_ON(end < 0); /* We're not aware of other errors */
- return 0;
- }
+ return ret;
}
/**
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index b7532cb..fefb87a 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1992,10 +1992,12 @@ static void i915_hangcheck_elapsed(unsigned long data)
if (ring_idle(ring, seqno)) {
if (waitqueue_active(&ring->irq_queue)) {
/* Issue a wake-up to catch stuck h/w. */
- DRM_ERROR("Hangcheck timer elapsed... %s idle\n",
- ring->name);
+ if ((dev_priv->quirks & QUIRK_MISSED_SEQNO_INTERRUPTS) == 0) {
+ DRM_ERROR("Hangcheck timer elapsed... %s idle\n",
+ ring->name);
+ dev_priv->quirks |= QUIRK_MISSED_SEQNO_INTERRUPTS;
+ }
wake_up_all(&ring->irq_queue);
- ring->hangcheck.score += HUNG;
} else
busy = false;
} else {
--
1.8.4.rc3
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