From patchwork Thu Mar 26 17:44:05 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joakim Tjernlund X-Patchwork-Id: 25163 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id 18E6ADDEDD for ; Fri, 27 Mar 2009 04:44:54 +1100 (EST) X-Original-To: linuxppc-dev@ozlabs.org Delivered-To: linuxppc-dev@ozlabs.org Received: from gw1.transmode.se (gw1.transmode.se [213.115.205.20]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id B00A7DDE0E for ; Fri, 27 Mar 2009 04:44:11 +1100 (EST) Received: from tmnt04.transmode.se (tmnt04.transmode.se [192.168.46.15]) by gw1.transmode.se (Postfix) with ESMTP id A62206A7DB for ; Thu, 26 Mar 2009 18:44:07 +0100 (CET) Received: from gentoo-jocke.transmode.se ([192.168.1.15]) by tmnt04.transmode.se over TLS secured channel with Microsoft SMTPSVC(5.0.2195.6713); Thu, 26 Mar 2009 18:44:07 +0100 Received: from gentoo-jocke.transmode.se (localhost.localdomain [127.0.0.1]) by gentoo-jocke.transmode.se (8.14.0/8.14.0) with ESMTP id n2QHi7cc028605; Thu, 26 Mar 2009 18:44:07 +0100 Received: (from jocke@localhost) by gentoo-jocke.transmode.se (8.14.0/8.14.0/Submit) id n2QHi5cn028604; Thu, 26 Mar 2009 18:44:05 +0100 From: Joakim Tjernlund To: avorontsov@ru.mvista.com, leoli@freescale.com, linuxppc-dev@ozlabs.org, netdev@vger.kernel.org Subject: [PATCH] ucc_geth: Rework the TX logic. Date: Thu, 26 Mar 2009 18:44:05 +0100 Message-Id: <1238089445-28396-1-git-send-email-Joakim.Tjernlund@transmode.se> X-Mailer: git-send-email 1.6.1.3 X-OriginalArrivalTime: 26 Mar 2009 17:44:07.0432 (UTC) FILETIME=[76633880:01C9AE3A] Cc: Joakim Tjernlund X-BeenThere: linuxppc-dev@ozlabs.org X-Mailman-Version: 2.1.11 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@ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org The line: if ((bd == ugeth->txBd[txQ]) && (netif_queue_stopped(dev) == 0)) break; in ucc_geth_tx() didn not make sense to me. Rework & cleanup this logic to something understandable. --- Reworked the patch according to Antons comments. drivers/net/ucc_geth.c | 66 +++++++++++++++++++++++++++-------------------- 1 files changed, 38 insertions(+), 28 deletions(-) diff --git a/drivers/net/ucc_geth.c b/drivers/net/ucc_geth.c index 7fc91aa..465de3a 100644 --- a/drivers/net/ucc_geth.c +++ b/drivers/net/ucc_geth.c @@ -161,6 +161,17 @@ static struct ucc_geth_info ugeth_primary_info = { static struct ucc_geth_info ugeth_info[8]; + +static inline u32 __iomem *bd2buf(u8 __iomem *bd) +{ + return (u32 __iomem *)(bd+4); +} + +static inline u32 __iomem *bd2status(u8 __iomem *bd) +{ + return (u32 __iomem *)bd; +} + #ifdef DEBUG static void mem_disp(u8 *addr, int size) { @@ -3048,6 +3059,7 @@ static int ucc_geth_start_xmit(struct sk_buff *skb, struct net_device *dev) u8 __iomem *bd; /* BD pointer */ u32 bd_status; u8 txQ = 0; + int tx_ind; ugeth_vdbg("%s: IN", __func__); @@ -3057,21 +3069,19 @@ static int ucc_geth_start_xmit(struct sk_buff *skb, struct net_device *dev) /* Start from the next BD that should be filled */ bd = ugeth->txBd[txQ]; - bd_status = in_be32((u32 __iomem *)bd); + bd_status = in_be32(bd2status(bd)); /* Save the skb pointer so we can free it later */ - ugeth->tx_skbuff[txQ][ugeth->skb_curtx[txQ]] = skb; + tx_ind = ugeth->skb_curtx[txQ]; + ugeth->tx_skbuff[txQ][tx_ind] = skb; /* Update the current skb pointer (wrapping if this was the last) */ - ugeth->skb_curtx[txQ] = - (ugeth->skb_curtx[txQ] + - 1) & TX_RING_MOD_MASK(ugeth->ug_info->bdRingLenTx[txQ]); + tx_ind = (tx_ind + 1) & TX_RING_MOD_MASK(ugeth->ug_info->bdRingLenTx[txQ]); + ugeth->skb_curtx[txQ] = tx_ind; /* set up the buffer descriptor */ - out_be32(&((struct qe_bd __iomem *)bd)->buf, - dma_map_single(&ugeth->dev->dev, skb->data, - skb->len, DMA_TO_DEVICE)); - - /* printk(KERN_DEBUG"skb->data is 0x%x\n",skb->data); */ + out_be32(bd2buf(bd), + dma_map_single(&ugeth->dev->dev, skb->data, + skb->len, DMA_TO_DEVICE)); bd_status = (bd_status & T_W) | T_R | T_I | T_L | skb->len; @@ -3088,9 +3098,9 @@ static int ucc_geth_start_xmit(struct sk_buff *skb, struct net_device *dev) /* If the next BD still needs to be cleaned up, then the bds are full. We need to tell the kernel to stop sending us stuff. */ - if (bd == ugeth->confBd[txQ]) { - if (!netif_queue_stopped(dev)) - netif_stop_queue(dev); + + if (!in_be32(bd2buf(bd))) { + netif_stop_queue(dev); } ugeth->txBd[txQ] = bd; @@ -3198,41 +3208,41 @@ static int ucc_geth_tx(struct net_device *dev, u8 txQ) struct ucc_geth_private *ugeth = netdev_priv(dev); u8 __iomem *bd; /* BD pointer */ u32 bd_status; + int tx_ind, num_freed; bd = ugeth->confBd[txQ]; - bd_status = in_be32((u32 __iomem *)bd); - + bd_status = in_be32(bd2status(bd)); + tx_ind = ugeth->skb_dirtytx[txQ]; + num_freed = 0; /* Normal processing. */ while ((bd_status & T_R) == 0) { /* BD contains already transmitted buffer. */ /* Handle the transmitted buffer and release */ /* the BD to be used with the current frame */ - if ((bd == ugeth->txBd[txQ]) && (netif_queue_stopped(dev) == 0)) - break; + if (bd == ugeth->txBd[txQ]) + break; /* Queue is empty */ dev->stats.tx_packets++; /* Free the sk buffer associated with this TxBD */ - dev_kfree_skb(ugeth-> - tx_skbuff[txQ][ugeth->skb_dirtytx[txQ]]); - ugeth->tx_skbuff[txQ][ugeth->skb_dirtytx[txQ]] = NULL; - ugeth->skb_dirtytx[txQ] = - (ugeth->skb_dirtytx[txQ] + - 1) & TX_RING_MOD_MASK(ugeth->ug_info->bdRingLenTx[txQ]); - - /* We freed a buffer, so now we can restart transmission */ - if (netif_queue_stopped(dev)) - netif_wake_queue(dev); + dev_kfree_skb(ugeth->tx_skbuff[txQ][tx_ind]); + ugeth->tx_skbuff[txQ][tx_ind] = NULL; + out_be32(bd2buf(bd), 0); /* Mark it free */ + num_freed++; + tx_ind = (tx_ind + 1) & TX_RING_MOD_MASK(ugeth->ug_info->bdRingLenTx[txQ]); /* Advance the confirmation BD pointer */ if (!(bd_status & T_W)) bd += sizeof(struct qe_bd); else bd = ugeth->p_tx_bd_ring[txQ]; - bd_status = in_be32((u32 __iomem *)bd); + bd_status = in_be32(bd2status(bd)); } ugeth->confBd[txQ] = bd; + ugeth->skb_dirtytx[txQ] = tx_ind; + if (num_freed) + netif_wake_queue(dev); /* We freed some buffers, so restart transmission */ return 0; }