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[TG3]: Fix missing memory barriers and SD_STATUS_UPDATED bit clearing. 

There must be a rmb() between reading the status block tag
and calling tg3_has_work().  This was missing in tg3_mis()
and tg3_interrupt_tagged().  tg3_poll() got it right.

Also, SD_STATUS_UPDATED must be cleared in the status block
right before we call tg3_has_work().  Only tg3_poll() got this
wrong.

Based upon patches and commentary from Grant Grundler and
Michael Chan.

Signed-off-by: David S. Miller <davem@davemloft.net>
hifive-unleashed-5.1
David S. Miller 2005-06-24 20:17:10 -07:00
parent c54d7e03c3
commit cd024c8baf
1 changed files with 3 additions and 0 deletions
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3
drivers/net/tg3.c
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@ -2929,6 +2929,7 @@ static int tg3_poll(struct net_device *netdev, int *budget)
if (tp->tg3_flags & TG3_FLAG_TAGGED_STATUS)
tp->last_tag = sblk->status_tag;
rmb();
sblk->status &= ~SD_STATUS_UPDATED;
/* if no more work, tell net stack and NIC we're done */
done = !tg3_has_work(tp);
@ -2964,6 +2965,7 @@ static irqreturn_t tg3_msi(int irq, void *dev_id, struct pt_regs *regs)
*/
tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, 0x00000001);
tp->last_tag = sblk->status_tag;
rmb();
sblk->status &= ~SD_STATUS_UPDATED;
if (likely(tg3_has_work(tp)))
netif_rx_schedule(dev); /* schedule NAPI poll */
@ -3051,6 +3053,7 @@ static irqreturn_t tg3_interrupt_tagged(int irq, void *dev_id, struct pt_regs *r
tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW,
0x00000001);
tp->last_tag = sblk->status_tag;
rmb();
sblk->status &= ~SD_STATUS_UPDATED;
if (likely(tg3_has_work(tp)))
netif_rx_schedule(dev); /* schedule NAPI poll */