drm/amdgpu: use a timer for fence fallback
Less overhead than a work item and also adds proper cleanup handling.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 615ce6d..3630cb5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -389,7 +389,6 @@
* Fences.
*/
struct amdgpu_fence_driver {
- struct amdgpu_ring *ring;
uint64_t gpu_addr;
volatile uint32_t *cpu_addr;
/* sync_seq is protected by ring emission lock */
@@ -398,7 +397,7 @@
bool initialized;
struct amdgpu_irq_src *irq_src;
unsigned irq_type;
- struct delayed_work lockup_work;
+ struct timer_list fallback_timer;
wait_queue_head_t fence_queue;
};
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
index b92c193..257fce3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
@@ -85,24 +85,6 @@
}
/**
- * amdgpu_fence_schedule_check - schedule lockup check
- *
- * @ring: pointer to struct amdgpu_ring
- *
- * Queues a delayed work item to check for lockups.
- */
-static void amdgpu_fence_schedule_check(struct amdgpu_ring *ring)
-{
- /*
- * Do not reset the timer here with mod_delayed_work,
- * this can livelock in an interaction with TTM delayed destroy.
- */
- queue_delayed_work(system_power_efficient_wq,
- &ring->fence_drv.lockup_work,
- AMDGPU_FENCE_JIFFIES_TIMEOUT);
-}
-
-/**
* amdgpu_fence_emit - emit a fence on the requested ring
*
* @ring: ring the fence is associated with
@@ -136,6 +118,19 @@
}
/**
+ * amdgpu_fence_schedule_fallback - schedule fallback check
+ *
+ * @ring: pointer to struct amdgpu_ring
+ *
+ * Start a timer as fallback to our interrupts.
+ */
+static void amdgpu_fence_schedule_fallback(struct amdgpu_ring *ring)
+{
+ mod_timer(&ring->fence_drv.fallback_timer,
+ jiffies + AMDGPU_FENCE_JIFFIES_TIMEOUT);
+}
+
+/**
* amdgpu_fence_activity - check for fence activity
*
* @ring: pointer to struct amdgpu_ring
@@ -201,33 +196,12 @@
} while (atomic64_xchg(&ring->fence_drv.last_seq, seq) > seq);
if (seq < last_emitted)
- amdgpu_fence_schedule_check(ring);
+ amdgpu_fence_schedule_fallback(ring);
return wake;
}
/**
- * amdgpu_fence_check_lockup - check for hardware lockup
- *
- * @work: delayed work item
- *
- * Checks for fence activity and if there is none probe
- * the hardware if a lockup occured.
- */
-static void amdgpu_fence_check_lockup(struct work_struct *work)
-{
- struct amdgpu_fence_driver *fence_drv;
- struct amdgpu_ring *ring;
-
- fence_drv = container_of(work, struct amdgpu_fence_driver,
- lockup_work.work);
- ring = fence_drv->ring;
-
- if (amdgpu_fence_activity(ring))
- wake_up_all(&ring->fence_drv.fence_queue);
-}
-
-/**
* amdgpu_fence_process - process a fence
*
* @adev: amdgpu_device pointer
@@ -243,6 +217,20 @@
}
/**
+ * amdgpu_fence_fallback - fallback for hardware interrupts
+ *
+ * @work: delayed work item
+ *
+ * Checks for fence activity.
+ */
+static void amdgpu_fence_fallback(unsigned long arg)
+{
+ struct amdgpu_ring *ring = (void *)arg;
+
+ amdgpu_fence_process(ring);
+}
+
+/**
* amdgpu_fence_seq_signaled - check if a fence sequence number has signaled
*
* @ring: ring the fence is associated with
@@ -289,7 +277,7 @@
if (atomic64_read(&ring->fence_drv.last_seq) >= seq)
return 0;
- amdgpu_fence_schedule_check(ring);
+ amdgpu_fence_schedule_fallback(ring);
wait_event(ring->fence_drv.fence_queue, (
(signaled = amdgpu_fence_seq_signaled(ring, seq))));
@@ -490,9 +478,8 @@
atomic64_set(&ring->fence_drv.last_seq, 0);
ring->fence_drv.initialized = false;
- INIT_DELAYED_WORK(&ring->fence_drv.lockup_work,
- amdgpu_fence_check_lockup);
- ring->fence_drv.ring = ring;
+ setup_timer(&ring->fence_drv.fallback_timer, amdgpu_fence_fallback,
+ (unsigned long)ring);
init_waitqueue_head(&ring->fence_drv.fence_queue);
@@ -556,6 +543,7 @@
mutex_lock(&adev->ring_lock);
for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
struct amdgpu_ring *ring = adev->rings[i];
+
if (!ring || !ring->fence_drv.initialized)
continue;
r = amdgpu_fence_wait_empty(ring);
@@ -567,6 +555,7 @@
amdgpu_irq_put(adev, ring->fence_drv.irq_src,
ring->fence_drv.irq_type);
amd_sched_fini(&ring->sched);
+ del_timer_sync(&ring->fence_drv.fallback_timer);
ring->fence_drv.initialized = false;
}
mutex_unlock(&adev->ring_lock);
@@ -750,7 +739,8 @@
fence->fence_wake.func = amdgpu_fence_check_signaled;
__add_wait_queue(&ring->fence_drv.fence_queue, &fence->fence_wake);
fence_get(f);
- amdgpu_fence_schedule_check(ring);
+ if (!timer_pending(&ring->fence_drv.fallback_timer))
+ amdgpu_fence_schedule_fallback(ring);
FENCE_TRACE(&fence->base, "armed on ring %i!\n", ring->idx);
return true;
}