From patchwork Mon Aug 25 15:44:00 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Liu X-Patchwork-Id: 382766 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 6AC8A1400A3 for ; Tue, 26 Aug 2014 01:44:15 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933059AbaHYPoK (ORCPT ); Mon, 25 Aug 2014 11:44:10 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:50724 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933032AbaHYPoJ (ORCPT ); Mon, 25 Aug 2014 11:44:09 -0400 X-IronPort-AV: E=Sophos;i="5.04,397,1406592000"; d="scan'208";a="165652786" Received: from ukmail1.uk.xensource.com (10.80.16.128) by smtprelay.citrix.com (10.13.107.79) with Microsoft SMTP Server id 14.3.181.6; Mon, 25 Aug 2014 11:44:01 -0400 Received: from dt47.uk.xensource.com ([10.80.229.47] helo=dt47.uk.xensource.com.) by ukmail1.uk.xensource.com with esmtp (Exim 4.69) (envelope-from ) id 1XLwR7-0008JO-7l; Mon, 25 Aug 2014 16:44:01 +0100 From: Wei Liu To: , CC: , Wei Liu , Ian Campbell Subject: [PATCH net] xen-netback: move netif_napi_add before binding interrupt Date: Mon, 25 Aug 2014 16:44:00 +0100 Message-ID: <1408981440-19255-1-git-send-email-wei.liu2@citrix.com> X-Mailer: git-send-email 1.7.10.4 MIME-Version: 1.0 X-DLP: MIA1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 --- 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 e29e15d..f379689 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: