From patchwork Wed Feb 17 14:55:30 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anatolij Gustschin X-Patchwork-Id: 45638 X-Patchwork-Delegate: benh@kernel.crashing.org Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from bilbo.ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id BEF7FB8A4C for ; Thu, 18 Feb 2010 01:57:53 +1100 (EST) Received: by ozlabs.org (Postfix) id C2A57B8188; Thu, 18 Feb 2010 01:57:19 +1100 (EST) Delivered-To: linuxppc-dev@ozlabs.org Received: from mail-out.m-online.net (mail-out.m-online.net [212.18.0.10]) by ozlabs.org (Postfix) with ESMTP id 6C988B7FBE for ; Thu, 18 Feb 2010 01:57:19 +1100 (EST) Received: from mail01.m-online.net (mail.m-online.net [192.168.3.149]) by mail-out.m-online.net (Postfix) with ESMTP id 461991C00361; Wed, 17 Feb 2010 15:57:18 +0100 (CET) X-Auth-Info: PkGc5qo1T0+HE1X6uji8ZqNRs4UA0xkU6nm7va900po= Received: from localhost (p578FABF0.dip.t-dialin.net [87.143.171.240]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by mail.mnet-online.de (Postfix) with ESMTP id ED2F0902CB; Wed, 17 Feb 2010 15:57:17 +0100 (CET) From: Anatolij Gustschin To: netdev@vger.kernel.org Subject: [net-next-2.6 PATCH v2 3/3] fs_enet: add FEC TX buffer alignment workaround for MPC5121 Date: Wed, 17 Feb 2010 15:55:30 +0100 Message-Id: <1266418530-2727-4-git-send-email-agust@denx.de> X-Mailer: git-send-email 1.6.3.3 In-Reply-To: <1266418530-2727-3-git-send-email-agust@denx.de> References: <1266418530-2727-1-git-send-email-agust@denx.de> <1266418530-2727-2-git-send-email-agust@denx.de> <1266418530-2727-3-git-send-email-agust@denx.de> Cc: Wolfgang Denk , Detlev Zundel , linuxppc-dev@ozlabs.org, Anatolij Gustschin , "David S. Miller" , Piotr Ziecik X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org MPC5121 FEC requeries 4-byte alignmnent for TX data buffers. This patch is a work around that copies misaligned tx packets to an aligned skb before sending. Signed-off-by: John Rigby Signed-off-by: Piotr Ziecik Signed-off-by: Wolfgang Denk Signed-off-by: Anatolij Gustschin Acked-by: Grant Likely --- drivers/net/fs_enet/fs_enet-main.c | 44 ++++++++++++++++++++++++++++++++++++ 1 files changed, 44 insertions(+), 0 deletions(-) diff --git a/drivers/net/fs_enet/fs_enet-main.c b/drivers/net/fs_enet/fs_enet-main.c index 4297021..166a89d 100644 --- a/drivers/net/fs_enet/fs_enet-main.c +++ b/drivers/net/fs_enet/fs_enet-main.c @@ -580,6 +580,37 @@ void fs_cleanup_bds(struct net_device *dev) /**********************************************************************************/ +#ifdef CONFIG_FS_ENET_MPC5121_FEC +/* + * MPC5121 FEC requeries 4-byte alignment for TX data buffer! + */ +static struct sk_buff *tx_skb_align_workaround(struct net_device *dev, + struct sk_buff *skb) +{ + struct sk_buff *new_skb; + struct fs_enet_private *fep = netdev_priv(dev); + + /* Alloc new skb */ + new_skb = dev_alloc_skb(ENET_RX_FRSIZE + 4); + if (!new_skb) { + dev_warn(fep->dev, "Memory squeeze, dropping tx packet.\n"); + return NULL; + } + + /* Make sure new skb is properly aligned */ + skb_align(new_skb, 4); + + /* Copy data to new skb ... */ + skb_copy_from_linear_data(skb, new_skb->data, skb->len); + skb_put(new_skb, skb->len); + + /* ... and free an old one */ + dev_kfree_skb_any(skb); + + return new_skb; +} +#endif + static int fs_enet_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct fs_enet_private *fep = netdev_priv(dev); @@ -588,6 +619,19 @@ static int fs_enet_start_xmit(struct sk_buff *skb, struct net_device *dev) u16 sc; unsigned long flags; +#ifdef CONFIG_FS_ENET_MPC5121_FEC + if (((unsigned long)skb->data) & 0x3) { + skb = tx_skb_align_workaround(dev, skb); + if (!skb) { + /* + * We have lost packet due to memory allocation error + * in tx_skb_align_workaround(). Hopefully original + * skb is still valid, so try transmit it later. + */ + return NETDEV_TX_BUSY; + } + } +#endif spin_lock_irqsave(&fep->tx_lock, flags); /*