From 2557a933b795c1988c721ebb871cd735128bb9cb Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 7 Apr 2008 14:30:28 +1000 Subject: virtio: remove overzealous BUG_ON. The 'disable_cb' callback is designed as an optimization to tell the host we don't need callbacks now. As it is not reliable, the debug check is overzealous: it can happen on two CPUs at the same time. Document this. Even if it were reliable, the virtio_net driver doesn't disable callbacks on transmit so the START_USE/END_USE debugging reentrance protection can be easily tripped even on UP. Thanks to Balaji Rao for the bug report and testing. Signed-off-by: Rusty Russell CC: Balaji Rao Signed-off-by: Linus Torvalds --- drivers/virtio/virtio_ring.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index aa714028641..c2fa5c63081 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -214,10 +214,7 @@ static void vring_disable_cb(struct virtqueue *_vq) { struct vring_virtqueue *vq = to_vvq(_vq); - START_USE(vq); - BUG_ON(vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT); vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT; - END_USE(vq); } static bool vring_enable_cb(struct virtqueue *_vq) -- cgit v1.2.3