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[PATCH] Fix locking in gianfar

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This patch fixes several bugs in the gianfar driver, including a major one
where spinlocks were horribly broken:

* Split gianfar locks into two types: TX and RX
* Made it so gfar_start() now clears RHALT
* Fixed a bug where calling gfar_start_xmit() with interrupts off would
corrupt the interrupt state
* Fixed a bug where a frame could potentially arrive, and never be handled
(if no more frames arrived
* Fixed a bug where the rx_work_limit would never be observed by the rx
completion code
* Fixed a bug where the interrupt handlers were not actually protected by
their spinlocks

Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Andy Fleming
2006-04-20 16:44:29 -05:00
committed by Jeff Garzik
parent f18b95c3e2
commit fef6108d45
4 changed files with 100 additions and 67 deletions
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56
drivers/net/gianfar.c
View File

@ -210,7 +210,8 @@ static int gfar_probe(struct platform_device *pdev)
goto regs_fail;
}
spin_lock_init(&priv->lock);
spin_lock_init(&priv->txlock);
spin_lock_init(&priv->rxlock);
platform_set_drvdata(pdev, dev);
@ -515,11 +516,13 @@ void stop_gfar(struct net_device *dev)
phy_stop(priv->phydev);
/* Lock it down */
spin_lock_irqsave(&priv->lock, flags);
spin_lock_irqsave(&priv->txlock, flags);
spin_lock(&priv->rxlock);
gfar_halt(dev);
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock(&priv->rxlock);
spin_unlock_irqrestore(&priv->txlock, flags);
/* Free the IRQs */
if (priv->einfo->device_flags & FSL_GIANFAR_DEV_HAS_MULTI_INTR) {
@ -605,14 +608,15 @@ void gfar_start(struct net_device *dev)
tempval |= DMACTRL_INIT_SETTINGS;
gfar_write(&priv->regs->dmactrl, tempval);
/* Clear THLT, so that the DMA starts polling now */
gfar_write(&regs->tstat, TSTAT_CLEAR_THALT);
/* Make sure we aren't stopped */
tempval = gfar_read(&priv->regs->dmactrl);
tempval &= ~(DMACTRL_GRS | DMACTRL_GTS);
gfar_write(&priv->regs->dmactrl, tempval);
/* Clear THLT/RHLT, so that the DMA starts polling now */
gfar_write(&regs->tstat, TSTAT_CLEAR_THALT);
gfar_write(&regs->rstat, RSTAT_CLEAR_RHALT);
/* Unmask the interrupts we look for */
gfar_write(&regs->imask, IMASK_DEFAULT);
}
@ -928,12 +932,13 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
struct txfcb *fcb = NULL;
struct txbd8 *txbdp;
u16 status;
unsigned long flags;
/* Update transmit stats */
priv->stats.tx_bytes += skb->len;
/* Lock priv now */
spin_lock_irq(&priv->lock);
spin_lock_irqsave(&priv->txlock, flags);
/* Point at the first free tx descriptor */
txbdp = priv->cur_tx;
@ -1004,7 +1009,7 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
gfar_write(&priv->regs->tstat, TSTAT_CLEAR_THALT);
/* Unlock priv */
spin_unlock_irq(&priv->lock);
spin_unlock_irqrestore(&priv->txlock, flags);
return 0;
}
@ -1049,7 +1054,7 @@ static void gfar_vlan_rx_register(struct net_device *dev,
unsigned long flags;
u32 tempval;
spin_lock_irqsave(&priv->lock, flags);
spin_lock_irqsave(&priv->rxlock, flags);
priv->vlgrp = grp;
@ -1076,7 +1081,7 @@ static void gfar_vlan_rx_register(struct net_device *dev,
gfar_write(&priv->regs->rctrl, tempval);
}
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock_irqrestore(&priv->rxlock, flags);
}
@ -1085,12 +1090,12 @@ static void gfar_vlan_rx_kill_vid(struct net_device *dev, uint16_t vid)
struct gfar_private *priv = netdev_priv(dev);
unsigned long flags;
spin_lock_irqsave(&priv->lock, flags);
spin_lock_irqsave(&priv->rxlock, flags);
if (priv->vlgrp)
priv->vlgrp->vlan_devices[vid] = NULL;
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock_irqrestore(&priv->rxlock, flags);
}
@ -1179,7 +1184,7 @@ static irqreturn_t gfar_transmit(int irq, void *dev_id, struct pt_regs *regs)
gfar_write(&priv->regs->ievent, IEVENT_TX_MASK);
/* Lock priv */
spin_lock(&priv->lock);
spin_lock(&priv->txlock);
bdp = priv->dirty_tx;
while ((bdp->status & TXBD_READY) == 0) {
/* If dirty_tx and cur_tx are the same, then either the */
@ -1224,7 +1229,7 @@ static irqreturn_t gfar_transmit(int irq, void *dev_id, struct pt_regs *regs)
else
gfar_write(&priv->regs->txic, 0);
spin_unlock(&priv->lock);
spin_unlock(&priv->txlock);
return IRQ_HANDLED;
}
@ -1305,9 +1310,10 @@ irqreturn_t gfar_receive(int irq, void *dev_id, struct pt_regs *regs)
{
struct net_device *dev = (struct net_device *) dev_id;
struct gfar_private *priv = netdev_priv(dev);
#ifdef CONFIG_GFAR_NAPI
u32 tempval;
#else
unsigned long flags;
#endif
/* Clear IEVENT, so rx interrupt isn't called again
@ -1330,7 +1336,7 @@ irqreturn_t gfar_receive(int irq, void *dev_id, struct pt_regs *regs)
}
#else
spin_lock(&priv->lock);
spin_lock_irqsave(&priv->rxlock, flags);
gfar_clean_rx_ring(dev, priv->rx_ring_size);
/* If we are coalescing interrupts, update the timer */
@ -1341,7 +1347,7 @@ irqreturn_t gfar_receive(int irq, void *dev_id, struct pt_regs *regs)
else
gfar_write(&priv->regs->rxic, 0);
spin_unlock(&priv->lock);
spin_unlock_irqrestore(&priv->rxlock, flags);
#endif
return IRQ_HANDLED;
@ -1490,13 +1496,6 @@ int gfar_clean_rx_ring(struct net_device *dev, int rx_work_limit)
/* Update the current rxbd pointer to be the next one */
priv->cur_rx = bdp;
/* If no packets have arrived since the
* last one we processed, clear the IEVENT RX and
* BSY bits so that another interrupt won't be
* generated when we set IMASK */
if (bdp->status & RXBD_EMPTY)
gfar_write(&priv->regs->ievent, IEVENT_RX_MASK);
return howmany;
}
@ -1516,7 +1515,7 @@ static int gfar_poll(struct net_device *dev, int *budget)
rx_work_limit -= howmany;
*budget -= howmany;
if (rx_work_limit >= 0) {
if (rx_work_limit > 0) {
netif_rx_complete(dev);
/* Clear the halt bit in RSTAT */
@ -1533,7 +1532,8 @@ static int gfar_poll(struct net_device *dev, int *budget)
gfar_write(&priv->regs->rxic, 0);
}
return (rx_work_limit < 0) ? 1 : 0;
/* Return 1 if there's more work to do */
return (rx_work_limit > 0) ? 0 : 1;
}
#endif
@ -1629,7 +1629,7 @@ static void adjust_link(struct net_device *dev)
struct phy_device *phydev = priv->phydev;
int new_state = 0;
spin_lock_irqsave(&priv->lock, flags);
spin_lock_irqsave(&priv->txlock, flags);
if (phydev->link) {
u32 tempval = gfar_read(&regs->maccfg2);
u32 ecntrl = gfar_read(&regs->ecntrl);
@ -1694,7 +1694,7 @@ static void adjust_link(struct net_device *dev)
if (new_state && netif_msg_link(priv))
phy_print_status(phydev);
spin_unlock_irqrestore(&priv->lock, flags);
spin_unlock_irqrestore(&priv->txlock, flags);
}
/* Update the hash table based on the current list of multicast