diff options
| author | Michael Chan <mchan@broadcom.com> | 2007-07-08 09:51:03 +0400 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-07-11 09:18:35 +0400 |
| commit | b8a7ce7bedb2134acb731e08e588ad92087a40ff (patch) | |
| tree | 2d18138f5c9697f71861c37f94aa2e7cbfc5228b /drivers | |
| parent | 9b1084b8f99a6b5e97c0c9bc1b4455db4fa51a07 (diff) | |
| download | linux-b8a7ce7bedb2134acb731e08e588ad92087a40ff.tar.xz | |
[BNX2]: Reduce spurious INTA interrupts.
Spurious interrupts are often encountered especially on systems
using the 8259 PIC mode. This is because the I/O write to deassert
the interrupt is posted and won't get to the chip immediately. As
a result, the IRQ may remain asserted after the IRQ handler exits,
causing spurious interrupts.
Add read back to flush the I/O write to deassert the IRQ immediately.
We also store the last_status_idx immediately in the IRQ handler to
help detect whether the interrupt is ours or not when the IRQ is
entered again before ->poll gets called.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/bnx2.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c index 439f4827addc..a806a8edec87 100644 --- a/drivers/net/bnx2.c +++ b/drivers/net/bnx2.c @@ -2547,6 +2547,7 @@ bnx2_interrupt(int irq, void *dev_instance) { struct net_device *dev = dev_instance; struct bnx2 *bp = netdev_priv(dev); + struct status_block *sblk = bp->status_blk; /* When using INTx, it is possible for the interrupt to arrive * at the CPU before the status block posted prior to the @@ -2554,7 +2555,7 @@ bnx2_interrupt(int irq, void *dev_instance) * When using MSI, the MSI message will always complete after * the status block write. */ - if ((bp->status_blk->status_idx == bp->last_status_idx) && + if ((sblk->status_idx == bp->last_status_idx) && (REG_RD(bp, BNX2_PCICFG_MISC_STATUS) & BNX2_PCICFG_MISC_STATUS_INTA_VALUE)) return IRQ_NONE; @@ -2563,11 +2564,19 @@ bnx2_interrupt(int irq, void *dev_instance) BNX2_PCICFG_INT_ACK_CMD_USE_INT_HC_PARAM | BNX2_PCICFG_INT_ACK_CMD_MASK_INT); + /* Read back to deassert IRQ immediately to avoid too many + * spurious interrupts. + */ + REG_RD(bp, BNX2_PCICFG_INT_ACK_CMD); + /* Return here if interrupt is shared and is disabled. */ if (unlikely(atomic_read(&bp->intr_sem) != 0)) return IRQ_HANDLED; - netif_rx_schedule(dev); + if (netif_rx_schedule_prep(dev)) { + bp->last_status_idx = sblk->status_idx; + __netif_rx_schedule(dev); + } return IRQ_HANDLED; } |