From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759999Ab2C3JYD (ORCPT ); Fri, 30 Mar 2012 05:24:03 -0400 Received: from mail-ee0-f46.google.com ([74.125.83.46]:58243 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754663Ab2C3JXy (ORCPT ); Fri, 30 Mar 2012 05:23:54 -0400 Message-ID: <1333099431.19659.15.camel@edumazet-laptop> Subject: Re: [PATCH v5 2/2] Ethernet driver for the WIZnet W5100 chip From: Eric Dumazet To: Mike Sinkovsky Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 30 Mar 2012 11:23:51 +0200 In-Reply-To: <1333090806-27988-2-git-send-email-msink@permonline.ru> References: <1332752876-1650-1-git-send-email-msink@permonline.ru> <1333090806-27988-2-git-send-email-msink@permonline.ru> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu3 Content-Transfer-Encoding: 8bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le vendredi 30 mars 2012 à 13:00 +0600, Mike Sinkovsky a écrit : > Tested and used in production with Blackfin BF531 embedded processor. > > Signed-off-by: Mike Sinkovsky > --- > + > +static int w5100_start_tx(struct sk_buff *skb, struct net_device *ndev) > +{ > + struct w5100_priv *priv = netdev_priv(ndev); > + u16 offset; > + > + if (w5100_read16(priv, W5100_S0_TX_FSR) < skb->len) { There is a race here. Interrupt came come right here before you set the stop_queue() > + netif_stop_queue(ndev); So Here I suggest adding a test again if (w5100_read16(priv, W5100_S0_TX_FSR) >= skb->len) netif_wake_queue(ndev); else return NETDEV_TX_BUSY; > + return NETDEV_TX_BUSY; > + } > + > + offset = w5100_read16(priv, W5100_S0_TX_WR); > + w5100_writebuf(priv, offset, skb->data, skb->len); > + w5100_write16(priv, W5100_S0_TX_WR, offset + skb->len); > + w5100_command(priv, S0_CR_SEND); > + ndev->stats.tx_bytes += skb->len; > + ndev->stats.tx_packets++; > + dev_kfree_skb(skb); > + > + return NETDEV_TX_OK; > +} > +