If we enter i915_handle_error() a second time and a global reset is
already in progress, we can simply wait for completion of the first
reset. Currently we exit early prior to the actual reset being
performed -- the worst of both worlds!
v2: Plug into the existing reset_queue, and remember that kselftests is
playing games with I915_RESET_BACKOFF to prevent hangcheck from screwing
up.
v3: Rename to i915_reset_device to fit in better with i915_reset_engine
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
Cc: Michel Thierry <michel.thierry@xxxxxxxxx>
Reviewed-by: Michel Thierry <michel.thierry@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_irq.c | 23 +++++++++++------------
drivers/gpu/drm/i915/selftests/intel_hangcheck.c | 4 ++++
2 files changed, 15 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 4cd9ee1ba332..8e9f4378b5a7 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -2600,13 +2600,13 @@ static irqreturn_t gen8_irq_handler(int irq, void *arg)
}
/**
- * i915_reset_and_wakeup - do process context error handling work
+ * i915_reset_device - do process context error handling work
* @dev_priv: i915 device private
*
* Fire an error uevent so userspace can see that a hang or error
* was detected.
*/
-static void i915_reset_and_wakeup(struct drm_i915_private *dev_priv)
+static void i915_reset_device(struct drm_i915_private *dev_priv)
{
struct kobject *kobj = &dev_priv->drm.primary->kdev->kobj;
char *error_event[] = { I915_ERROR_UEVENT "=1", NULL };
@@ -2646,13 +2646,6 @@ static void i915_reset_and_wakeup(struct drm_i915_private *dev_priv)
if (!test_bit(I915_WEDGED, &dev_priv->gpu_error.flags))
kobject_uevent_env(kobj,
KOBJ_CHANGE, reset_done_event);
-
- /*
- * Note: The wake_up also serves as a memory barrier so that
- * waiters see the updated value of the dev_priv->gpu_error.
- */
- clear_bit(I915_RESET_BACKOFF, &dev_priv->gpu_error.flags);
- wake_up_all(&dev_priv->gpu_error.reset_queue);
}
static inline void
@@ -2744,11 +2737,17 @@ void i915_handle_error(struct drm_i915_private *dev_priv,
if (!engine_mask)
goto out;
- if (test_and_set_bit(I915_RESET_BACKOFF,
- &dev_priv->gpu_error.flags))
+ if (test_and_set_bit(I915_RESET_BACKOFF, &dev_priv->gpu_error.flags)) {
+ wait_event(dev_priv->gpu_error.reset_queue,
+ !test_bit(I915_RESET_BACKOFF,
+ &dev_priv->gpu_error.flags));
goto out;
+ }
+
+ i915_reset_device(dev_priv);
- i915_reset_and_wakeup(dev_priv);
+ clear_bit(I915_RESET_BACKOFF, &dev_priv->gpu_error.flags);
+ wake_up_all(&dev_priv->gpu_error.reset_queue);
out:
intel_runtime_pm_put(dev_priv);
diff --git a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
index aa31d6c0cdfb..cc00a361f0fa 100644
--- a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
+++ b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
@@ -316,6 +316,8 @@ static int igt_global_reset(void *arg)
GEM_BUG_ON(test_bit(I915_RESET_HANDOFF, &i915->gpu_error.flags));
clear_bit(I915_RESET_BACKOFF, &i915->gpu_error.flags);
+ wake_up_all(&i915->gpu_error.reset_queue);
+
if (i915_terminally_wedged(&i915->gpu_error))
err = -EIO;
@@ -404,6 +406,7 @@ static int igt_wait_reset(void *arg)
unlock:
mutex_unlock(&i915->drm.struct_mutex);
clear_bit(I915_RESET_BACKOFF, &i915->gpu_error.flags);
+ wake_up_all(&i915->gpu_error.reset_queue);
if (i915_terminally_wedged(&i915->gpu_error))
return -EIO;
@@ -519,6 +522,7 @@ static int igt_reset_queue(void *arg)
unlock:
mutex_unlock(&i915->drm.struct_mutex);
clear_bit(I915_RESET_BACKOFF, &i915->gpu_error.flags);
+ wake_up_all(&i915->gpu_error.reset_queue);
if (i915_terminally_wedged(&i915->gpu_error))
return -EIO;
--
2.11.0
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