From e24f8191cc35ae3780b4656a6befae8b8657edc2 Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Mon, 25 Aug 2014 16:44:00 +0100 Subject: [PATCH] xen-netback: move netif_napi_add before binding interrupt Interrupt is enabled when bind_interdomain_evtchn_to_irqhandler returns. If there's interrupt pending interrupt handler is invoked. NAPI needs to be initialised before binding interrupt otherwise the interrupt handler will try to scheduling a NAPI instance that is not initialised yet, resulting in kernel OOPS. This fixes a regression introduced in ea2c5e13 ("xen-netback: move NAPI add/remove calls"). Ideally function calls to create kthreads should also be moved before binding but I intent to fix this regression with minimal changes and refactor the code with another patch. Reported-by: Thomas Leonard Signed-off-by: Wei Liu Cc: Ian Campbell Signed-off-by: David S. Miller --- drivers/net/xen-netback/interface.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index e29e15dca86e..f379689dde30 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -576,6 +576,9 @@ int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref, init_waitqueue_head(&queue->dealloc_wq); atomic_set(&queue->inflight_packets, 0); + netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll, + XENVIF_NAPI_WEIGHT); + if (tx_evtchn == rx_evtchn) { /* feature-split-event-channels == 0 */ err = bind_interdomain_evtchn_to_irqhandler( @@ -629,9 +632,6 @@ int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref, wake_up_process(queue->task); wake_up_process(queue->dealloc_task); - netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll, - XENVIF_NAPI_WEIGHT); - return 0; err_rx_unbind: -- 2.20.1