From cd024c8baf9756759c57f0a19be639da8d3d4f8c Mon Sep 17 00:00:00 2001 From: "David S. Miller" <davem@davemloft.net> Date: Fri, 24 Jun 2005 20:17:10 -0700 Subject: [PATCH] [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> --- drivers/net/tg3.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c index a0b8848049c9e..fef1d087107c1 100644 --- a/drivers/net/tg3.c +++ b/drivers/net/tg3.c @@ -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 */ -- GitLab