Commit 39126abc authored by Dave Airlie's avatar Dave Airlie
Browse files

nouveau: offload fence uevents work to workqueue 



This should break the deadlock between the fctx lock and the irq lock.

This offloads the processing off the work from the irq into a workqueue.

Cc: linux-stable@vger.kernel.org
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/576237/
parent b5e69be1

drivers/gpu/drm/nouveau/nouveau_fence.c

+18 −6
Original line number Diff line number Diff line
@@ -103,6 +103,7 @@ nouveau_fence_context_kill(struct nouveau_fence_chan *fctx, int error) 
void

nouveau_fence_context_del(struct nouveau_fence_chan *fctx)

{

	cancel_work_sync(&fctx->uevent_work);

	nouveau_fence_context_kill(fctx, 0);

	nvif_event_dtor(&fctx->event);

	fctx->dead = 1;
@@ -145,12 +146,13 @@ nouveau_fence_update(struct nouveau_channel *chan, struct nouveau_fence_chan *fc 
	return drop;

}



static int

nouveau_fence_wait_uevent_handler(struct nvif_event *event, void *repv, u32 repc)

static void

nouveau_fence_uevent_work(struct work_struct *work)

{

	struct nouveau_fence_chan *fctx = container_of(event, typeof(*fctx), event);

	struct nouveau_fence_chan *fctx = container_of(work, struct nouveau_fence_chan,

						       uevent_work);

	unsigned long flags;

	int ret = NVIF_EVENT_KEEP;

	int drop = 0;



	spin_lock_irqsave(&fctx->lock, flags);

	if (!list_empty(&fctx->pending)) {
@@ -160,11 +162,20 @@ nouveau_fence_wait_uevent_handler(struct nvif_event *event, void *repv, u32 repc 
		fence = list_entry(fctx->pending.next, typeof(*fence), head);

		chan = rcu_dereference_protected(fence->channel, lockdep_is_held(&fctx->lock));

		if (nouveau_fence_update(chan, fctx))

			ret = NVIF_EVENT_DROP;

			drop = 1;

	}

	if (drop)

		nvif_event_block(&fctx->event);



	spin_unlock_irqrestore(&fctx->lock, flags);

}



	return ret;

static int

nouveau_fence_wait_uevent_handler(struct nvif_event *event, void *repv, u32 repc)

{

	struct nouveau_fence_chan *fctx = container_of(event, typeof(*fctx), event);

	schedule_work(&fctx->uevent_work);

	return NVIF_EVENT_KEEP;

}



void
@@ -178,6 +189,7 @@ nouveau_fence_context_new(struct nouveau_channel *chan, struct nouveau_fence_cha 
	} args;

	int ret;



	INIT_WORK(&fctx->uevent_work, nouveau_fence_uevent_work);

	INIT_LIST_HEAD(&fctx->flip);

	INIT_LIST_HEAD(&fctx->pending);

	spin_lock_init(&fctx->lock);

drivers/gpu/drm/nouveau/nouveau_fence.h

+1 −0
Original line number Diff line number Diff line
@@ -44,6 +44,7 @@ struct nouveau_fence_chan { 
	u32 context;

	char name[32];



	struct work_struct uevent_work;

	struct nvif_event event;

	int notify_ref, dead, killed;

};