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gianfar: Support NAPI for TX Frames
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Poll the completed TX frames in gfar_poll().  This prevents the tx
completion interrupt from interfering with processing of received
frames.

We also disable hardware rx coalescing when NAPI is enabled.

Signed-off-by: Dai Haruki <dai.haruki@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
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Dai Haruki authored and Jeff Garzik committed Apr 17, 2008
1 parent 0b50d75 commit d080cd6
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Showing 2 changed files with 53 additions and 16 deletions.
56 changes: 42 additions & 14 deletions drivers/net/gianfar.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1250,17 +1250,12 @@ static void gfar_timeout(struct net_device *dev)
}

/* Interrupt Handler for Transmit complete */
static irqreturn_t gfar_transmit(int irq, void *dev_id)
int gfar_clean_tx_ring(struct net_device *dev)
{
struct net_device *dev = (struct net_device *) dev_id;
struct gfar_private *priv = netdev_priv(dev);
struct txbd8 *bdp;
struct gfar_private *priv = netdev_priv(dev);
int howmany = 0;

/* Clear IEVENT */
gfar_write(&priv->regs->ievent, IEVENT_TX_MASK);

/* Lock priv */
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 */
Expand All @@ -1269,7 +1264,7 @@ static irqreturn_t gfar_transmit(int irq, void *dev_id)
if ((bdp == priv->cur_tx) && (netif_queue_stopped(dev) == 0))
break;

dev->stats.tx_packets++;
howmany++;

/* Deferred means some collisions occurred during transmit, */
/* but we eventually sent the packet. */
Expand All @@ -1278,11 +1273,15 @@ static irqreturn_t gfar_transmit(int irq, void *dev_id)

/* Free the sk buffer associated with this TxBD */
dev_kfree_skb_irq(priv->tx_skbuff[priv->skb_dirtytx]);

priv->tx_skbuff[priv->skb_dirtytx] = NULL;
priv->skb_dirtytx =
(priv->skb_dirtytx +
1) & TX_RING_MOD_MASK(priv->tx_ring_size);

/* Clean BD length for empty detection */
bdp->length = 0;

/* update bdp to point at next bd in the ring (wrapping if necessary) */
if (bdp->status & TXBD_WRAP)
bdp = priv->tx_bd_base;
Expand All @@ -1297,6 +1296,25 @@ static irqreturn_t gfar_transmit(int irq, void *dev_id)
netif_wake_queue(dev);
} /* while ((bdp->status & TXBD_READY) == 0) */

dev->stats.tx_packets += howmany;

return howmany;
}

/* Interrupt Handler for Transmit complete */
static irqreturn_t gfar_transmit(int irq, void *dev_id)
{
struct net_device *dev = (struct net_device *) dev_id;
struct gfar_private *priv = netdev_priv(dev);

/* Clear IEVENT */
gfar_write(&priv->regs->ievent, IEVENT_TX_MASK);

/* Lock priv */
spin_lock(&priv->txlock);

gfar_clean_tx_ring(dev);

/* If we are coalescing the interrupts, reset the timer */
/* Otherwise, clear it */
if (likely(priv->txcoalescing)) {
Expand Down Expand Up @@ -1392,15 +1410,15 @@ irqreturn_t gfar_receive(int irq, void *dev_id)
unsigned long flags;
#endif

/* Clear IEVENT, so rx interrupt isn't called again
* because of this interrupt */
gfar_write(&priv->regs->ievent, IEVENT_RX_MASK);

/* support NAPI */
#ifdef CONFIG_GFAR_NAPI
/* Clear IEVENT, so interrupts aren't called again
* because of the packets that have already arrived */
gfar_write(&priv->regs->ievent, IEVENT_RTX_MASK);

if (netif_rx_schedule_prep(dev, &priv->napi)) {
tempval = gfar_read(&priv->regs->imask);
tempval &= IMASK_RX_DISABLED;
tempval &= IMASK_RTX_DISABLED;
gfar_write(&priv->regs->imask, tempval);

__netif_rx_schedule(dev, &priv->napi);
Expand All @@ -1411,6 +1429,9 @@ irqreturn_t gfar_receive(int irq, void *dev_id)
gfar_read(&priv->regs->imask));
}
#else
/* Clear IEVENT, so rx interrupt isn't called again
* because of this interrupt */
gfar_write(&priv->regs->ievent, IEVENT_RX_MASK);

spin_lock_irqsave(&priv->rxlock, flags);
gfar_clean_rx_ring(dev, priv->rx_ring_size);
Expand Down Expand Up @@ -1580,6 +1601,13 @@ static int gfar_poll(struct napi_struct *napi, int budget)
struct gfar_private *priv = container_of(napi, struct gfar_private, napi);
struct net_device *dev = priv->dev;
int howmany;
unsigned long flags;

/* If we fail to get the lock, don't bother with the TX BDs */
if (spin_trylock_irqsave(&priv->txlock, flags)) {
gfar_clean_tx_ring(dev);
spin_unlock_irqrestore(&priv->txlock, flags);
}

howmany = gfar_clean_rx_ring(dev, budget);

Expand Down
13 changes: 11 additions & 2 deletions drivers/net/gianfar.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -126,9 +126,16 @@ extern const char gfar_driver_version[];
#define DEFAULT_TXCOUNT 16
#define DEFAULT_TXTIME 21

#define DEFAULT_RXTIME 21

/* Non NAPI Case */
#ifndef CONFIG_GFAR_NAPI
#define DEFAULT_RX_COALESCE 1
#define DEFAULT_RXCOUNT 16
#define DEFAULT_RXTIME 21
#else
#define DEFAULT_RX_COALESCE 0
#define DEFAULT_RXCOUNT 0
#endif /* CONFIG_GFAR_NAPI */

#define TBIPA_VALUE 0x1f
#define MIIMCFG_INIT_VALUE 0x00000007
Expand Down Expand Up @@ -242,6 +249,7 @@ extern const char gfar_driver_version[];
#define IEVENT_PERR 0x00000001
#define IEVENT_RX_MASK (IEVENT_RXB0 | IEVENT_RXF0)
#define IEVENT_TX_MASK (IEVENT_TXB | IEVENT_TXF)
#define IEVENT_RTX_MASK (IEVENT_RX_MASK | IEVENT_TX_MASK)
#define IEVENT_ERR_MASK \
(IEVENT_RXC | IEVENT_BSY | IEVENT_EBERR | IEVENT_MSRO | \
IEVENT_BABT | IEVENT_TXC | IEVENT_TXE | IEVENT_LC \
Expand Down Expand Up @@ -269,11 +277,12 @@ extern const char gfar_driver_version[];
#define IMASK_FIQ 0x00000004
#define IMASK_DPE 0x00000002
#define IMASK_PERR 0x00000001
#define IMASK_RX_DISABLED ~(IMASK_RXFEN0 | IMASK_BSY)
#define IMASK_DEFAULT (IMASK_TXEEN | IMASK_TXFEN | IMASK_TXBEN | \
IMASK_RXFEN0 | IMASK_BSY | IMASK_EBERR | IMASK_BABR | \
IMASK_XFUN | IMASK_RXC | IMASK_BABT | IMASK_DPE \
| IMASK_PERR)
#define IMASK_RTX_DISABLED ((~(IMASK_RXFEN0 | IMASK_TXFEN | IMASK_BSY)) \
& IMASK_DEFAULT)

/* Fifo management */
#define FIFO_TX_THR_MASK 0x01ff
Expand Down

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