gianfar: Add per queue structure support

This patch introduces per tx and per rx queue structures.
Earlier the members of these structures were inside the
gfar_private structure.

Moving forward if we want to support multiple queues, we need
to refactor the gfar_private structure so that introduction of
multiple queues is easier.
Signed-off-by: Sandeep Gopalpet <Sandeep.Kumar@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/gianfar.h

@@ -7,8 +7,9 @@
  *
  * Author: Andy Fleming
  * Maintainer: Kumar Gala
+ * Modifier: Sandeep Gopalpet <sandeep.kumar@freescale.com>
  *
- * Copyright (c) 2002-2004 Freescale Semiconductor, Inc.
+ * Copyright 2002-2009 Freescale Semiconductor, Inc.
  *
  * This program is free software; you can redistribute  it and/or modify it
  * under  the terms of  the GNU General  Public License as published by the
@@ -699,62 +700,95 @@ struct gfar {
 #define FSL_GIANFAR_DEV_HAS_BD_STASHING		0x00000200
 #define FSL_GIANFAR_DEV_HAS_BUF_STASHING	0x00000400
 
-/* Struct stolen almost completely (and shamelessly) from the FCC enet source
- * (Ok, that's not so true anymore, but there is a family resemblence)
- * The GFAR buffer descriptors track the ring buffers.  The rx_bd_base
- * and tx_bd_base always point to the currently available buffer.
- * The dirty_tx tracks the current buffer that is being sent by the
- * controller.  The cur_tx and dirty_tx are equal under both completely
- * empty and completely full conditions.  The empty/ready indicator in
- * the buffer descriptor determines the actual condition.
+/**
+ *	struct gfar_priv_tx_q - per tx queue structure
+ *	@txlock: per queue tx spin lock
+ *	@tx_skbuff:skb pointers
+ *	@skb_curtx: to be used skb pointer
+ *	@skb_dirtytx:the last used skb pointer
+ *	@qindex: index of this queue
+ *	@dev: back pointer to the dev structure
+ *	@grp: back pointer to the group to which this queue belongs
+ *	@tx_bd_base: First tx buffer descriptor
+ *	@cur_tx: Next free ring entry
+ *	@dirty_tx: First buffer in line to be transmitted
+ *	@tx_ring_size: Tx ring size
+ *	@num_txbdfree: number of free TxBds
+ *	@txcoalescing: enable/disable tx coalescing
+ *	@txic: transmit interrupt coalescing value
+ *	@txcount: coalescing value if based on tx frame count
+ *	@txtime: coalescing value if based on time
  */
-struct gfar_private {
-	/* Fields controlled by TX lock */
-	spinlock_t txlock;
-
-	/* Pointer to the array of skbuffs */
+struct gfar_priv_tx_q {
+	spinlock_t txlock __attribute__ ((aligned (SMP_CACHE_BYTES)));
 	struct sk_buff ** tx_skbuff;
-
-	/* next free skb in the array */
+	/* Buffer descriptor pointers */
+	dma_addr_t tx_bd_dma_base;
+	struct	txbd8 *tx_bd_base;
+	struct	txbd8 *cur_tx;
+	struct	txbd8 *dirty_tx;
+	struct	net_device *dev;
 	u16	skb_curtx;
-
-	/* First skb in line to be transmitted */
 	u16	skb_dirtytx;
-
+	u16	qindex;
+	unsigned int tx_ring_size;
+	unsigned int num_txbdfree;
 	/* Configuration info for the coalescing features */
 	unsigned char txcoalescing;
 	unsigned long txic;
+	unsigned short txcount;
+	unsigned short txtime;
+};
 
-	/* Buffer descriptor pointers */
-	dma_addr_t tx_bd_dma_base;
-	struct txbd8 *tx_bd_base;	/* First tx buffer descriptor */
-	struct txbd8 *cur_tx;	        /* Next free ring entry */
-	struct txbd8 *dirty_tx;		/* First buffer in line
-					   to be transmitted */
-	unsigned int tx_ring_size;
-	unsigned int num_txbdfree;	/* number of TxBDs free */
-
-	/* RX Locked fields */
-	spinlock_t rxlock;
+/**
+ *	struct gfar_priv_rx_q - per rx queue structure
+ *	@rxlock: per queue rx spin lock
+ *	@napi: the napi poll function
+ *	@rx_skbuff: skb pointers
+ *	@skb_currx: currently use skb pointer
+ *	@rx_bd_base: First rx buffer descriptor
+ *	@cur_rx: Next free rx ring entry
+ *	@qindex: index of this queue
+ *	@dev: back pointer to the dev structure
+ *	@rx_ring_size: Rx ring size
+ *	@rxcoalescing: enable/disable rx-coalescing
+ *	@rxic: receive interrupt coalescing vlaue
+ */
 
-	struct device_node *node;
-	struct net_device *ndev;
-	struct of_device *ofdev;
+struct gfar_priv_rx_q {
+	spinlock_t rxlock __attribute__ ((aligned (SMP_CACHE_BYTES)));
 	struct	napi_struct napi;
-
-	/* skb array and index */
 	struct	sk_buff ** rx_skbuff;
+	struct	rxbd8 *rx_bd_base;
+	struct	rxbd8 *cur_rx;
+	struct	net_device *dev;
 	u16	skb_currx;
-
+	u16	qindex;
+	unsigned int	rx_ring_size;
 	/* RX Coalescing values */
 	unsigned char rxcoalescing;
 	unsigned long rxic;
+};
+
+/* Struct stolen almost completely (and shamelessly) from the FCC enet source
+ * (Ok, that's not so true anymore, but there is a family resemblence)
+ * The GFAR buffer descriptors track the ring buffers.  The rx_bd_base
+ * and tx_bd_base always point to the currently available buffer.
+ * The dirty_tx tracks the current buffer that is being sent by the
+ * controller.  The cur_tx and dirty_tx are equal under both completely
+ * empty and completely full conditions.  The empty/ready indicator in
+ * the buffer descriptor determines the actual condition.
+ */
+struct gfar_private {
 
-	struct rxbd8 *rx_bd_base;	/* First Rx buffers */
-	struct rxbd8 *cur_rx;           /* Next free rx ring entry */
+	struct device_node *node;
+	struct net_device *ndev;
+	struct of_device *ofdev;
 
-	/* RX parameters */
-	unsigned int rx_ring_size;
+	struct gfar_priv_tx_q *tx_queue;
+	struct gfar_priv_rx_q *rx_queue;
+
+	/* RX per device parameters */
 	unsigned int rx_buffer_size;
 	unsigned int rx_stash_size;
 	unsigned int rx_stash_index;

drivers/net/gianfar_ethtool.c

@@ -7,8 +7,9 @@
  *
  *  Author: Andy Fleming
  *  Maintainer: Kumar Gala
+ *  Modifier: Sandeep Gopalpet <sandeep.kumar@freescale.com>
  *
- *  Copyright (c) 2003,2004 Freescale Semiconductor, Inc.
+ *  Copyright 2003-2006, 2008-2009 Freescale Semiconductor, Inc.
  *
  *  This software may be used and distributed according to
  *  the terms of the GNU Public License, Version 2, incorporated herein
@@ -41,7 +42,7 @@
 #include "gianfar.h"
 
 extern void gfar_start(struct net_device *dev);
-extern int gfar_clean_rx_ring(struct net_device *dev, int rx_work_limit);
+extern int gfar_clean_rx_ring(struct gfar_priv_rx_q *rx_queue, int rx_work_limit);
 
 #define GFAR_MAX_COAL_USECS 0xffff
 #define GFAR_MAX_COAL_FRAMES 0xff
@@ -197,12 +198,16 @@ static int gfar_gsettings(struct net_device *dev, struct ethtool_cmd *cmd)
 {
 	struct gfar_private *priv = netdev_priv(dev);
 	struct phy_device *phydev = priv->phydev;
+	struct gfar_priv_rx_q *rx_queue = NULL;
+	struct gfar_priv_tx_q *tx_queue = NULL;
 
 	if (NULL == phydev)
 		return -ENODEV;
+	tx_queue = priv->tx_queue;
+	rx_queue = priv->rx_queue;
 
-	cmd->maxtxpkt = get_icft_value(priv->txic);
-	cmd->maxrxpkt = get_icft_value(priv->rxic);
+	cmd->maxtxpkt = get_icft_value(tx_queue->txic);
+	cmd->maxrxpkt = get_icft_value(rx_queue->rxic);
 
 	return phy_ethtool_gset(phydev, cmd);
 }
@@ -279,6 +284,8 @@ static unsigned int gfar_ticks2usecs(struct gfar_private *priv, unsigned int tic
 static int gfar_gcoalesce(struct net_device *dev, struct ethtool_coalesce *cvals)
 {
 	struct gfar_private *priv = netdev_priv(dev);
+	struct gfar_priv_rx_q *rx_queue = NULL;
+	struct gfar_priv_tx_q *tx_queue = NULL;
 	unsigned long rxtime;
 	unsigned long rxcount;
 	unsigned long txtime;
@@ -290,10 +297,13 @@ static int gfar_gcoalesce(struct net_device *dev, struct ethtool_coalesce *cvals
 	if (NULL == priv->phydev)
 		return -ENODEV;
 
-	rxtime  = get_ictt_value(priv->rxic);
-	rxcount = get_icft_value(priv->rxic);
-	txtime  = get_ictt_value(priv->txic);
-	txcount = get_icft_value(priv->txic);
+	rx_queue = priv->rx_queue;
+	tx_queue = priv->tx_queue;
+
+	rxtime  = get_ictt_value(rx_queue->rxic);
+	rxcount = get_icft_value(rx_queue->rxic);
+	txtime  = get_ictt_value(tx_queue->txic);
+	txcount = get_icft_value(tx_queue->txic);
 	cvals->rx_coalesce_usecs = gfar_ticks2usecs(priv, rxtime);
 	cvals->rx_max_coalesced_frames = rxcount;
 
@@ -339,16 +349,21 @@ static int gfar_gcoalesce(struct net_device *dev, struct ethtool_coalesce *cvals
 static int gfar_scoalesce(struct net_device *dev, struct ethtool_coalesce *cvals)
 {
 	struct gfar_private *priv = netdev_priv(dev);
+	struct gfar_priv_tx_q *tx_queue = NULL;
+	struct gfar_priv_rx_q *rx_queue = NULL;
 
 	if (!(priv->device_flags & FSL_GIANFAR_DEV_HAS_COALESCE))
 		return -EOPNOTSUPP;
 
+	tx_queue = priv->tx_queue;
+	rx_queue = priv->rx_queue;
+
 	/* Set up rx coalescing */
 	if ((cvals->rx_coalesce_usecs == 0) ||
 	    (cvals->rx_max_coalesced_frames == 0))
-		priv->rxcoalescing = 0;
+		rx_queue->rxcoalescing = 0;
 	else
-		priv->rxcoalescing = 1;
+		rx_queue->rxcoalescing = 1;
 
 	if (NULL == priv->phydev)
 		return -ENODEV;
@@ -366,15 +381,15 @@ static int gfar_scoalesce(struct net_device *dev, struct ethtool_coalesce *cvals
 		return -EINVAL;
 	}
 
-	priv->rxic = mk_ic_value(cvals->rx_max_coalesced_frames,
+	rx_queue->rxic = mk_ic_value(cvals->rx_max_coalesced_frames,
 		gfar_usecs2ticks(priv, cvals->rx_coalesce_usecs));
 
 	/* Set up tx coalescing */
 	if ((cvals->tx_coalesce_usecs == 0) ||
 	    (cvals->tx_max_coalesced_frames == 0))
-		priv->txcoalescing = 0;
+		tx_queue->txcoalescing = 0;
 	else
-		priv->txcoalescing = 1;
+		tx_queue->txcoalescing = 1;
 
 	/* Check the bounds of the values */
 	if (cvals->tx_coalesce_usecs > GFAR_MAX_COAL_USECS) {
@@ -389,16 +404,16 @@ static int gfar_scoalesce(struct net_device *dev, struct ethtool_coalesce *cvals
 		return -EINVAL;
 	}
 
-	priv->txic = mk_ic_value(cvals->tx_max_coalesced_frames,
+	tx_queue->txic = mk_ic_value(cvals->tx_max_coalesced_frames,
 		gfar_usecs2ticks(priv, cvals->tx_coalesce_usecs));
 
 	gfar_write(&priv->regs->rxic, 0);
-	if (priv->rxcoalescing)
-		gfar_write(&priv->regs->rxic, priv->rxic);
+	if (rx_queue->rxcoalescing)
+		gfar_write(&priv->regs->rxic, rx_queue->rxic);
 
 	gfar_write(&priv->regs->txic, 0);
-	if (priv->txcoalescing)
-		gfar_write(&priv->regs->txic, priv->txic);
+	if (tx_queue->txcoalescing)
+		gfar_write(&priv->regs->txic, tx_queue->txic);
 
 	return 0;
 }
@@ -409,6 +424,11 @@ static int gfar_scoalesce(struct net_device *dev, struct ethtool_coalesce *cvals
 static void gfar_gringparam(struct net_device *dev, struct ethtool_ringparam *rvals)
 {
 	struct gfar_private *priv = netdev_priv(dev);
+	struct gfar_priv_tx_q *tx_queue = NULL;
+	struct gfar_priv_rx_q *rx_queue = NULL;
+
+	tx_queue = priv->tx_queue;
+	rx_queue = priv->rx_queue;
 
 	rvals->rx_max_pending = GFAR_RX_MAX_RING_SIZE;
 	rvals->rx_mini_max_pending = GFAR_RX_MAX_RING_SIZE;
@@ -418,10 +438,10 @@ static void gfar_gringparam(struct net_device *dev, struct ethtool_ringparam *rv
 	/* Values changeable by the user.  The valid values are
 	 * in the range 1 to the "*_max_pending" counterpart above.
 	 */
-	rvals->rx_pending = priv->rx_ring_size;
-	rvals->rx_mini_pending = priv->rx_ring_size;
-	rvals->rx_jumbo_pending = priv->rx_ring_size;
-	rvals->tx_pending = priv->tx_ring_size;
+	rvals->rx_pending = rx_queue->rx_ring_size;
+	rvals->rx_mini_pending = rx_queue->rx_ring_size;
+	rvals->rx_jumbo_pending = rx_queue->rx_ring_size;
+	rvals->tx_pending = tx_queue->tx_ring_size;
 }
 
 /* Change the current ring parameters, stopping the controller if
@@ -431,6 +451,8 @@ static void gfar_gringparam(struct net_device *dev, struct ethtool_ringparam *rv
 static int gfar_sringparam(struct net_device *dev, struct ethtool_ringparam *rvals)
 {
 	struct gfar_private *priv = netdev_priv(dev);
+	struct gfar_priv_tx_q *tx_queue = NULL;
+	struct gfar_priv_rx_q *rx_queue = NULL;
 	int err = 0;
 
 	if (rvals->rx_pending > GFAR_RX_MAX_RING_SIZE)
@@ -451,29 +473,32 @@ static int gfar_sringparam(struct net_device *dev, struct ethtool_ringparam *rva
 		return -EINVAL;
 	}
 
+	tx_queue = priv->tx_queue;
+	rx_queue = priv->rx_queue;
+
 	if (dev->flags & IFF_UP) {
 		unsigned long flags;
 
 		/* Halt TX and RX, and process the frames which
 		 * have already been received */
-		spin_lock_irqsave(&priv->txlock, flags);
-		spin_lock(&priv->rxlock);
+		spin_lock_irqsave(&tx_queue->txlock, flags);
+		spin_lock(&rx_queue->rxlock);
 
 		gfar_halt(dev);
 
-		spin_unlock(&priv->rxlock);
-		spin_unlock_irqrestore(&priv->txlock, flags);
+		spin_unlock(&rx_queue->rxlock);
+		spin_unlock_irqrestore(&tx_queue->txlock, flags);
 
-		gfar_clean_rx_ring(dev, priv->rx_ring_size);
+		gfar_clean_rx_ring(rx_queue, rx_queue->rx_ring_size);
 
 		/* Now we take down the rings to rebuild them */
 		stop_gfar(dev);
 	}
 
 	/* Change the size */
-	priv->rx_ring_size = rvals->rx_pending;
-	priv->tx_ring_size = rvals->tx_pending;
-	priv->num_txbdfree = priv->tx_ring_size;
+	rx_queue->rx_ring_size = rvals->rx_pending;
+	tx_queue->tx_ring_size = rvals->tx_pending;
+	tx_queue->num_txbdfree = tx_queue->tx_ring_size;
 
 	/* Rebuild the rings with the new size */
 	if (dev->flags & IFF_UP) {
@@ -486,24 +511,29 @@ static int gfar_sringparam(struct net_device *dev, struct ethtool_ringparam *rva
 static int gfar_set_rx_csum(struct net_device *dev, uint32_t data)
 {
 	struct gfar_private *priv = netdev_priv(dev);
+	struct gfar_priv_rx_q *rx_queue = NULL;
+	struct gfar_priv_tx_q *tx_queue = NULL;
 	unsigned long flags;
 	int err = 0;
 
 	if (!(priv->device_flags & FSL_GIANFAR_DEV_HAS_CSUM))
 		return -EOPNOTSUPP;
 
+	tx_queue = priv->tx_queue;
+	rx_queue = priv->rx_queue;
+
 	if (dev->flags & IFF_UP) {
 		/* Halt TX and RX, and process the frames which
 		 * have already been received */
-		spin_lock_irqsave(&priv->txlock, flags);
-		spin_lock(&priv->rxlock);
+		spin_lock_irqsave(&tx_queue->txlock, flags);
+		spin_lock(&rx_queue->rxlock);
 
 		gfar_halt(dev);
 
-		spin_unlock(&priv->rxlock);
-		spin_unlock_irqrestore(&priv->txlock, flags);
+		spin_unlock(&rx_queue->rxlock);
+		spin_unlock_irqrestore(&tx_queue->txlock, flags);
 
-		gfar_clean_rx_ring(dev, priv->rx_ring_size);
+		gfar_clean_rx_ring(rx_queue, rx_queue->rx_ring_size);
 
 		/* Now we take down the rings to rebuild them */
 		stop_gfar(dev);

drivers/net/gianfar_sysfs.c

@@ -8,8 +8,9 @@
  *
  * Author: Andy Fleming
  * Maintainer: Kumar Gala (galak@kernel.crashing.org)
+ * Modifier: Sandeep Gopalpet <sandeep.kumar@freescale.com>
  *
- * Copyright (c) 2002-2005 Freescale Semiconductor, Inc.
+ * Copyright 2002-2009 Freescale Semiconductor, Inc.
  *
  * This program is free software; you can redistribute  it and/or modify it
  * under  the terms of  the GNU General  Public License as published by the
@@ -49,6 +50,7 @@ static ssize_t gfar_set_bd_stash(struct device *dev,
 				 const char *buf, size_t count)
 {
 	struct gfar_private *priv = netdev_priv(to_net_dev(dev));
+	struct gfar_priv_rx_q *rx_queue = NULL;
 	int new_setting = 0;
 	u32 temp;
 	unsigned long flags;
@@ -56,6 +58,8 @@ static ssize_t gfar_set_bd_stash(struct device *dev,
 	if (!(priv->device_flags & FSL_GIANFAR_DEV_HAS_BD_STASHING))
 		return count;
 
+	rx_queue = priv->rx_queue;
+
 	/* Find out the new setting */
 	if (!strncmp("on", buf, count - 1) || !strncmp("1", buf, count - 1))
 		new_setting = 1;
@@ -65,7 +69,7 @@ static ssize_t gfar_set_bd_stash(struct device *dev,
 	else
 		return count;
 
-	spin_lock_irqsave(&priv->rxlock, flags);
+	spin_lock_irqsave(&rx_queue->rxlock, flags);
 
 	/* Set the new stashing value */
 	priv->bd_stash_en = new_setting;
@@ -79,7 +83,7 @@ static ssize_t gfar_set_bd_stash(struct device *dev,
 
 	gfar_write(&priv->regs->attr, temp);
 
-	spin_unlock_irqrestore(&priv->rxlock, flags);
+	spin_unlock_irqrestore(&rx_queue->rxlock, flags);
 
 	return count;
 }
@@ -99,6 +103,7 @@ static ssize_t gfar_set_rx_stash_size(struct device *dev,
 				      const char *buf, size_t count)
 {
 	struct gfar_private *priv = netdev_priv(to_net_dev(dev));
+	struct gfar_priv_rx_q *rx_queue = NULL;
 	unsigned int length = simple_strtoul(buf, NULL, 0);
 	u32 temp;
 	unsigned long flags;
@@ -106,7 +111,9 @@ static ssize_t gfar_set_rx_stash_size(struct device *dev,
 	if (!(priv->device_flags & FSL_GIANFAR_DEV_HAS_BUF_STASHING))
 		return count;
 
-	spin_lock_irqsave(&priv->rxlock, flags);
+	rx_queue = priv->rx_queue;
+
+	spin_lock_irqsave(&rx_queue->rxlock, flags);
 	if (length > priv->rx_buffer_size)
 		goto out;
 
@@ -131,7 +138,7 @@ static ssize_t gfar_set_rx_stash_size(struct device *dev,
 	gfar_write(&priv->regs->attr, temp);
 
 out:
-	spin_unlock_irqrestore(&priv->rxlock, flags);
+	spin_unlock_irqrestore(&rx_queue->rxlock, flags);
 
 	return count;
 }
@@ -154,6 +161,7 @@ static ssize_t gfar_set_rx_stash_index(struct device *dev,
 				       const char *buf, size_t count)
 {
 	struct gfar_private *priv = netdev_priv(to_net_dev(dev));
+	struct gfar_priv_rx_q *rx_queue = NULL;
 	unsigned short index = simple_strtoul(buf, NULL, 0);
 	u32 temp;
 	unsigned long flags;
@@ -161,7 +169,9 @@ static ssize_t gfar_set_rx_stash_index(struct device *dev,
 	if (!(priv->device_flags & FSL_GIANFAR_DEV_HAS_BUF_STASHING))
 		return count;
 
-	spin_lock_irqsave(&priv->rxlock, flags);
+	rx_queue = priv->rx_queue;
+
+	spin_lock_irqsave(&rx_queue->rxlock, flags);
 	if (index > priv->rx_stash_size)
 		goto out;
 
@@ -176,7 +186,7 @@ static ssize_t gfar_set_rx_stash_index(struct device *dev,
 	gfar_write(&priv->regs->attreli, flags);
 
 out:
-	spin_unlock_irqrestore(&priv->rxlock, flags);
+	spin_unlock_irqrestore(&rx_queue->rxlock, flags);
 
 	return count;
 }
@@ -198,6 +208,7 @@ static ssize_t gfar_set_fifo_threshold(struct device *dev,
 				       const char *buf, size_t count)
 {
 	struct gfar_private *priv = netdev_priv(to_net_dev(dev));
+	struct gfar_priv_tx_q *tx_queue = NULL;
 	unsigned int length = simple_strtoul(buf, NULL, 0);
 	u32 temp;
 	unsigned long flags;
@@ -205,7 +216,9 @@ static ssize_t gfar_set_fifo_threshold(struct device *dev,
 	if (length > GFAR_MAX_FIFO_THRESHOLD)
 		return count;
 
-	spin_lock_irqsave(&priv->txlock, flags);
+	tx_queue = priv->tx_queue;
+
+	spin_lock_irqsave(&tx_queue->txlock, flags);
 
 	priv->fifo_threshold = length;
 
@@ -214,7 +227,7 @@ static ssize_t gfar_set_fifo_threshold(struct device *dev,
 	temp |= length;
 	gfar_write(&priv->regs->fifo_tx_thr, temp);
 
-	spin_unlock_irqrestore(&priv->txlock, flags);
+	spin_unlock_irqrestore(&tx_queue->txlock, flags);
 
 	return count;
 }
@@ -235,6 +248,7 @@ static ssize_t gfar_set_fifo_starve(struct device *dev,
 				    const char *buf, size_t count)
 {
 	struct gfar_private *priv = netdev_priv(to_net_dev(dev));
+	struct gfar_priv_tx_q *tx_queue = NULL;
 	unsigned int num = simple_strtoul(buf, NULL, 0);
 	u32 temp;
 	unsigned long flags;
@@ -242,7 +256,8 @@ static ssize_t gfar_set_fifo_starve(struct device *dev,
 	if (num > GFAR_MAX_FIFO_STARVE)
 		return count;
 
-	spin_lock_irqsave(&priv->txlock, flags);
+	tx_queue = priv->tx_queue;
+	spin_lock_irqsave(&tx_queue->txlock, flags);
 
 	priv->fifo_starve = num;
 
@@ -251,7 +266,7 @@ static ssize_t gfar_set_fifo_starve(struct device *dev,
 	temp |= num;
 	gfar_write(&priv->regs->fifo_tx_starve, temp);
 
-	spin_unlock_irqrestore(&priv->txlock, flags);
+	spin_unlock_irqrestore(&tx_queue->txlock, flags);
 
 	return count;
 }
@@ -273,6 +288,7 @@ static ssize_t gfar_set_fifo_starve_off(struct device *dev,
 					const char *buf, size_t count)
 {
 	struct gfar_private *priv = netdev_priv(to_net_dev(dev));
+	struct gfar_priv_tx_q *tx_queue = NULL;
 	unsigned int num = simple_strtoul(buf, NULL, 0);
 	u32 temp;
 	unsigned long flags;
@@ -280,7 +296,8 @@ static ssize_t gfar_set_fifo_starve_off(struct device *dev,
 	if (num > GFAR_MAX_FIFO_STARVE_OFF)
 		return count;
 
-	spin_lock_irqsave(&priv->txlock, flags);
+	tx_queue = priv->tx_queue;
+	spin_lock_irqsave(&tx_queue->txlock, flags);
 
 	priv->fifo_starve_off = num;
 
@@ -289,7 +306,7 @@ static ssize_t gfar_set_fifo_starve_off(struct device *dev,
 	temp |= num;
 	gfar_write(&priv->regs->fifo_tx_starve_shutoff, temp);
 
-	spin_unlock_irqrestore(&priv->txlock, flags);
+	spin_unlock_irqrestore(&tx_queue->txlock, flags);
 
 	return count;
 }