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Message-Id: <200805010408.m4148Cp0004875@goober>
Date: Thu, 1 May 2008 14:08:12 +1000
From: Greg Ungerer <gerg@...pgear.com>
To: torvalds@...ux-foundation.org
Cc: akpm@...ux-foundation.org, gerg@...inux.org,
linux-kernel@...r.kernel.org
Subject: [PATCH] m68knommu: fix FEC driver locking
From: Sebastian Siewior <bigeasy@...utronix.de>
It's easy: grab locks before talking to hardware and realease
them afterwards. The one big lock has been splitted into a hw_lock
and mii_lock.
Signed-off-by: Sebastian Siewior <bigeasy@...utronix.de>
Signed-off-by: Greg Ungerer <gerg@...inux.org>
---
diff -Naurp linux-2.6.25/drivers/net/fec.c linux-2.6.25-uc0/drivers/net/fec.c
--- linux-2.6.25/drivers/net/fec.c 2008-04-17 12:49:44.000000000 +1000
+++ linux-2.6.25-uc0/drivers/net/fec.c 2008-04-30 13:39:06.000000000 +1000
@@ -209,7 +209,10 @@ struct fec_enet_private {
cbd_t *cur_rx, *cur_tx; /* The next free ring entry */
cbd_t *dirty_tx; /* The ring entries to be free()ed. */
uint tx_full;
- spinlock_t lock;
+ /* hold while accessing the HW like ringbuffer for tx/rx but not MAC */
+ spinlock_t hw_lock;
+ /* hold while accessing the mii_list_t() elements */
+ spinlock_t mii_lock;
uint phy_id;
uint phy_id_done;
@@ -313,6 +316,7 @@ fec_enet_start_xmit(struct sk_buff *skb,
volatile fec_t *fecp;
volatile cbd_t *bdp;
unsigned short status;
+ unsigned long flags;
fep = netdev_priv(dev);
fecp = (volatile fec_t*)dev->base_addr;
@@ -322,6 +326,7 @@ fec_enet_start_xmit(struct sk_buff *skb,
return 1;
}
+ spin_lock_irqsave(&fep->hw_lock, flags);
/* Fill in a Tx ring entry */
bdp = fep->cur_tx;
@@ -332,6 +337,7 @@ fec_enet_start_xmit(struct sk_buff *skb,
* This should not happen, since dev->tbusy should be set.
*/
printk("%s: tx queue full!.\n", dev->name);
+ spin_unlock_irqrestore(&fep->hw_lock, flags);
return 1;
}
#endif
@@ -370,8 +376,6 @@ fec_enet_start_xmit(struct sk_buff *skb,
flush_dcache_range((unsigned long)skb->data,
(unsigned long)skb->data + skb->len);
- spin_lock_irq(&fep->lock);
-
/* Send it on its way. Tell FEC it's ready, interrupt when done,
* it's the last BD of the frame, and to put the CRC on the end.
*/
@@ -400,7 +404,7 @@ fec_enet_start_xmit(struct sk_buff *skb,
fep->cur_tx = (cbd_t *)bdp;
- spin_unlock_irq(&fep->lock);
+ spin_unlock_irqrestore(&fep->hw_lock, flags);
return 0;
}
@@ -458,19 +462,20 @@ fec_enet_interrupt(int irq, void * dev_i
struct net_device *dev = dev_id;
volatile fec_t *fecp;
uint int_events;
- int handled = 0;
+ irqreturn_t ret = IRQ_NONE;
fecp = (volatile fec_t*)dev->base_addr;
/* Get the interrupt events that caused us to be here.
*/
- while ((int_events = fecp->fec_ievent) != 0) {
+ do {
+ int_events = fecp->fec_ievent;
fecp->fec_ievent = int_events;
/* Handle receive event in its own function.
*/
if (int_events & FEC_ENET_RXF) {
- handled = 1;
+ ret = IRQ_HANDLED;
fec_enet_rx(dev);
}
@@ -479,17 +484,18 @@ fec_enet_interrupt(int irq, void * dev_i
them as part of the transmit process.
*/
if (int_events & FEC_ENET_TXF) {
- handled = 1;
+ ret = IRQ_HANDLED;
fec_enet_tx(dev);
}
if (int_events & FEC_ENET_MII) {
- handled = 1;
+ ret = IRQ_HANDLED;
fec_enet_mii(dev);
}
- }
- return IRQ_RETVAL(handled);
+ } while (int_events);
+
+ return ret;
}
@@ -502,7 +508,7 @@ fec_enet_tx(struct net_device *dev)
struct sk_buff *skb;
fep = netdev_priv(dev);
- spin_lock(&fep->lock);
+ spin_lock_irq(&fep->hw_lock);
bdp = fep->dirty_tx;
while (((status = bdp->cbd_sc) & BD_ENET_TX_READY) == 0) {
@@ -561,7 +567,7 @@ fec_enet_tx(struct net_device *dev)
}
}
fep->dirty_tx = (cbd_t *)bdp;
- spin_unlock(&fep->lock);
+ spin_unlock_irq(&fep->hw_lock);
}
@@ -588,6 +594,8 @@ fec_enet_rx(struct net_device *dev)
fep = netdev_priv(dev);
fecp = (volatile fec_t*)dev->base_addr;
+ spin_lock_irq(&fep->hw_lock);
+
/* First, grab all of the stats for the incoming packet.
* These get messed up if we get called due to a busy condition.
*/
@@ -693,6 +701,8 @@ while (!((status = bdp->cbd_sc) & BD_ENE
*/
fecp->fec_r_des_active = 0;
#endif
+
+ spin_unlock_irq(&fep->hw_lock);
}
@@ -706,11 +716,11 @@ fec_enet_mii(struct net_device *dev)
uint mii_reg;
fep = netdev_priv(dev);
+ spin_lock_irq(&fep->mii_lock);
+
ep = fep->hwp;
mii_reg = ep->fec_mii_data;
- spin_lock(&fep->lock);
-
if ((mip = mii_head) == NULL) {
printk("MII and no head!\n");
goto unlock;
@@ -727,7 +737,7 @@ fec_enet_mii(struct net_device *dev)
ep->fec_mii_data = mip->mii_regval;
unlock:
- spin_unlock(&fep->lock);
+ spin_unlock_irq(&fep->mii_lock);
}
static int
@@ -741,12 +751,11 @@ mii_queue(struct net_device *dev, int re
/* Add PHY address to register command.
*/
fep = netdev_priv(dev);
- regval |= fep->phy_addr << 23;
+ spin_lock_irqsave(&fep->mii_lock, flags);
+ regval |= fep->phy_addr << 23;
retval = 0;
- spin_lock_irqsave(&fep->lock,flags);
-
if ((mip = mii_free) != NULL) {
mii_free = mip->mii_next;
mip->mii_regval = regval;
@@ -763,9 +772,8 @@ mii_queue(struct net_device *dev, int re
retval = 1;
}
- spin_unlock_irqrestore(&fep->lock,flags);
-
- return(retval);
+ spin_unlock_irqrestore(&fep->mii_lock, flags);
+ return retval;
}
static void mii_do_cmd(struct net_device *dev, const phy_cmd_t *c)
@@ -2308,6 +2316,9 @@ int __init fec_enet_init(struct net_devi
return -ENOMEM;
}
+ spin_lock_init(&fep->hw_lock);
+ spin_lock_init(&fep->mii_lock);
+
/* Create an Ethernet device instance.
*/
fecp = (volatile fec_t *) fec_hw[index];
--
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