From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757688Ab3LFMpp (ORCPT ); Fri, 6 Dec 2013 07:45:45 -0500 Received: from lvk-gate.cs.msu.ru ([188.44.42.233]:47237 "EHLO mail.lvk.cs.msu.su" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753406Ab3LFMpo (ORCPT ); Fri, 6 Dec 2013 07:45:44 -0500 X-Greylist: delayed 575 seconds by postgrey-1.27 at vger.kernel.org; Fri, 06 Dec 2013 07:45:43 EST X-Spam-ASN: From: Nikita Yushchenko To: "David S. Miller" , Claudiu Manoil , netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Dmitry Krivoschekov , Konstantin Baydarov , Nikita Yushchenko Subject: [PATCH] net: gainfar: fix race between issuing and completing Tx Date: Fri, 6 Dec 2013 16:35:59 +0400 Message-Id: <1386333359-18854-1-git-send-email-nyushchenko@dev.rtsoft.ru> X-Mailer: git-send-email 1.7.0.1 X-AV-Checked: ClamAV using ClamSMTP Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org gfar_poll() checked Tx queue status without locking, thus allowing gfar_start_xmit() to alter it in parallel, which caused hang on every other nfsroot boot with RT enabled. This patch raises locking from gfar_clean_tx_ring() up to gfar_poll(). With this change applied, hangs are no longer reproduced. Signed-off-by: Nikita Yushchenko --- drivers/net/ethernet/freescale/gianfar.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c index 0343a14..9ac1946 100644 --- a/drivers/net/ethernet/freescale/gianfar.c +++ b/drivers/net/ethernet/freescale/gianfar.c @@ -2499,7 +2499,6 @@ static void gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) skb_dirtytx = tx_queue->skb_dirtytx; while ((skb = tx_queue->tx_skbuff[skb_dirtytx])) { - unsigned long flags; frags = skb_shinfo(skb)->nr_frags; @@ -2561,9 +2560,7 @@ static void gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) TX_RING_MOD_MASK(tx_ring_size); howmany++; - spin_lock_irqsave(&tx_queue->txlock, flags); tx_queue->num_txbdfree += nr_txbds; - spin_unlock_irqrestore(&tx_queue->txlock, flags); } /* If we freed a buffer, we can restart transmission, if necessary */ @@ -2838,6 +2835,7 @@ static int gfar_poll(struct napi_struct *napi, int budget) int has_tx_work; unsigned long rstat_rxf; int num_act_queues; + unsigned long flags; /* Clear IEVENT, so interrupts aren't called again * because of the packets that have already arrived @@ -2854,11 +2852,13 @@ static int gfar_poll(struct napi_struct *napi, int budget) has_tx_work = 0; for_each_set_bit(i, &gfargrp->tx_bit_map, priv->num_tx_queues) { tx_queue = priv->tx_queue[i]; + spin_lock_irqsave(&tx_queue->txlock, flags); /* run Tx cleanup to completion */ if (tx_queue->tx_skbuff[tx_queue->skb_dirtytx]) { gfar_clean_tx_ring(tx_queue); has_tx_work = 1; } + spin_unlock_irqrestore(&tx_queue->txlock, flags); } for_each_set_bit(i, &gfargrp->rx_bit_map, priv->num_rx_queues) { -- 1.7.0.1