From patchwork Mon Mar 19 21:23:53 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haiyang Zhang X-Patchwork-Id: 147627 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 99C4DB6FA1 for ; Tue, 20 Mar 2012 08:17:34 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755180Ab2CSVRQ (ORCPT ); Mon, 19 Mar 2012 17:17:16 -0400 Received: from p3plsmtps2ded03.prod.phx3.secureserver.net ([208.109.80.60]:42255 "HELO p3plsmtps2ded03-01.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755081Ab2CSVRN (ORCPT ); Mon, 19 Mar 2012 17:17:13 -0400 Received: (qmail 18079 invoked from network); 19 Mar 2012 21:17:12 -0000 Received: from unknown (HELO linuxonhyperv.com) (72.167.245.219) by p3plsmtps2ded03-01.prod.phx3.secureserver.net (208.109.80.60) with ESMTP; 19 Mar 2012 21:17:12 -0000 Received: by linuxonhyperv.com (Postfix, from userid 503) id BE5B819019F; Mon, 19 Mar 2012 14:24:15 -0700 (PDT) From: Haiyang Zhang To: haiyangz@microsoft.com, kys@microsoft.com, davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org Subject: [PATCH v2,1/1] net/hyperv: Fix the code handling tx busy Date: Mon, 19 Mar 2012 14:23:53 -0700 Message-Id: <1332192233-32305-2-git-send-email-haiyangz@microsoft.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1332192233-32305-1-git-send-email-haiyangz@microsoft.com> References: <1332192233-32305-1-git-send-email-haiyangz@microsoft.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Instead of dropping the packet, we keep the skb buffer, and return NETDEV_TX_BUSY to let upper layer retry send. This will not cause endless loop, because the host is taking data away from ring buffer, and we have called the stop_queue before returning NETDEV_TX_BUSY. The stop_queue was called in the function netvsc_send() in file netvsc.c, then it returns to rndis_filter_send(), which returns to netvsc_start_xmit() in file netvsc_drv.c. So the NETDEV_TX_BUSY is indeed returned AFTER queue is stopped. Signed-off-by: Haiyang Zhang Reviewed-by: K. Y. Srinivasan Acked-by: Eric Dumazet --- drivers/net/hyperv/netvsc_drv.c | 5 +---- 1 files changed, 1 insertions(+), 4 deletions(-) diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 2517d20..dd29478 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -223,13 +223,10 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) net->stats.tx_bytes += skb->len; net->stats.tx_packets++; } else { - /* we are shutting down or bus overloaded, just drop packet */ - net->stats.tx_dropped++; kfree(packet); - dev_kfree_skb_any(skb); } - return NETDEV_TX_OK; + return ret ? NETDEV_TX_BUSY : NETDEV_TX_OK; } /*