drm/i915: Separate GPU hang waitqueue from advance
Currently __i915_wait_request uses a per-engine wait_queue_t for the dual
purpose of waking after the GPU advances or for waking after an error.
In the future, we may add even more wake sources and require greater
separation, but for now we can conceptually simplify wakeups by separating
the two sources. In particular, this allows us to use different wait-queues
(e.g. one on the engine advancement, a global one for errors and one on
each requests) without any hassle.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467390209-3576-5-git-send-email-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 4948c90..0d0e4ac 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1410,6 +1410,12 @@
#define I915_WEDGED (1 << 31)
/**
+ * Waitqueue to signal when a hang is detected. Used to for waiters
+ * to release the struct_mutex for the reset to procede.
+ */
+ wait_queue_head_t wait_queue;
+
+ /**
* Waitqueue to signal when the reset has completed. Used by clients
* that wait for dev_priv->mm.wedged to settle.
*/
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e0b1e28..b5278d1 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1455,6 +1455,7 @@
const bool irq_test_in_progress =
ACCESS_ONCE(dev_priv->gpu_error.test_irq_rings) & intel_engine_flag(engine);
int state = interruptible ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE;
+ DEFINE_WAIT(reset);
DEFINE_WAIT(wait);
unsigned long timeout_expire;
s64 before = 0; /* Only to silence a compiler warning. */
@@ -1499,6 +1500,7 @@
goto out;
}
+ add_wait_queue(&dev_priv->gpu_error.wait_queue, &reset);
for (;;) {
struct timer_list timer;
@@ -1557,6 +1559,8 @@
destroy_timer_on_stack(&timer);
}
}
+ remove_wait_queue(&dev_priv->gpu_error.wait_queue, &reset);
+
if (!irq_test_in_progress)
engine->irq_put(engine);
@@ -5287,6 +5291,7 @@
i915_gem_retire_work_handler);
INIT_DELAYED_WORK(&dev_priv->mm.idle_work,
i915_gem_idle_work_handler);
+ init_waitqueue_head(&dev_priv->gpu_error.wait_queue);
init_waitqueue_head(&dev_priv->gpu_error.reset_queue);
dev_priv->relative_constants_mode = I915_EXEC_CONSTANTS_REL_GENERAL;
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 83f40ba..6c17596 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -2488,11 +2488,8 @@
return ret;
}
-static void i915_error_wake_up(struct drm_i915_private *dev_priv,
- bool reset_completed)
+static void i915_error_wake_up(struct drm_i915_private *dev_priv)
{
- struct intel_engine_cs *engine;
-
/*
* Notify all waiters for GPU completion events that reset state has
* been changed, and that they need to restart their wait after
@@ -2501,18 +2498,10 @@
*/
/* Wake up __wait_seqno, potentially holding dev->struct_mutex. */
- for_each_engine(engine, dev_priv)
- wake_up_all(&engine->irq_queue);
+ wake_up_all(&dev_priv->gpu_error.wait_queue);
/* Wake up intel_crtc_wait_for_pending_flips, holding crtc->mutex. */
wake_up_all(&dev_priv->pending_flip_queue);
-
- /*
- * Signal tasks blocked in i915_gem_wait_for_error that the pending
- * reset state is cleared.
- */
- if (reset_completed)
- wake_up_all(&dev_priv->gpu_error.reset_queue);
}
/**
@@ -2577,7 +2566,7 @@
* Note: The wake_up also serves as a memory barrier so that
* waiters see the update value of the reset counter atomic_t.
*/
- i915_error_wake_up(dev_priv, true);
+ wake_up_all(&dev_priv->gpu_error.reset_queue);
}
}
@@ -2714,7 +2703,7 @@
* ensure that the waiters see the updated value of the reset
* counter atomic_t.
*/
- i915_error_wake_up(dev_priv, false);
+ i915_error_wake_up(dev_priv);
}
i915_reset_and_wakeup(dev_priv);