[TG3]: Fix missing memory barriers and SD_STATUS_UPDATED bit clearing. (cd024c8b) · Commits · 戴 / test

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 −0

Original line number	Diff line number	Diff line
		@@ -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 */

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