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Commit 38f3843e authored by Michael Chan's avatar Michael Chan Committed by David S. Miller
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[TG3]: Use status tag to check for new events 



Use the status tag to determine if there are new events in
tg3_interrupt_tagged(). We discussed about this a while ago with Grant
Grundler and DaveM. This scheme makes it unnecessary to clear the
updated bit in the status block when using tagged mode, and only
a simple comparison is needed to determine if there are new events.

The tp->lock around netif_rx_complete() and tg3_restart_ints() is also
removed. It is unnecessary with DaveM's new locking scheme.

Signed-off-by: default avatarMichael Chan <mchan@broadcom.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 61487480

drivers/net/tg3.c

+15 −17
Original line number Diff line number Diff line
@@ -488,7 +488,8 @@ static void tg3_disable_ints(struct tg3 *tp) 


static inline void tg3_cond_int(struct tg3 *tp)

{

	if (tp->hw_status->status & SD_STATUS_UPDATED)

	if (!(tp->tg3_flags & TG3_FLAG_TAGGED_STATUS) &&

	    (tp->hw_status->status & SD_STATUS_UPDATED))

		tw32(GRC_LOCAL_CTRL, tp->grc_local_ctrl | GRC_LCLCTRL_SETINT);

}
@@ -3220,18 +3221,17 @@ static int tg3_poll(struct net_device *netdev, int *budget) 
		netdev->quota -= work_done;

	}



	if (tp->tg3_flags & TG3_FLAG_TAGGED_STATUS)

	if (tp->tg3_flags & TG3_FLAG_TAGGED_STATUS) {

		tp->last_tag = sblk->status_tag;

		rmb();

	} else

		sblk->status &= ~SD_STATUS_UPDATED;



	/* if no more work, tell net stack and NIC we're done */

	done = !tg3_has_work(tp);

	if (done) {

		spin_lock(&tp->lock);

		netif_rx_complete(netdev);

		tg3_restart_ints(tp);

		spin_unlock(&tp->lock);

	}



	return (done ? 0 : 1);
@@ -3351,7 +3351,7 @@ static irqreturn_t tg3_interrupt_tagged(int irq, void *dev_id, struct pt_regs *r 
	 * Reading the PCI State register will confirm whether the

	 * interrupt is ours and will flush the status block.

	 */

	if ((sblk->status & SD_STATUS_UPDATED) ||

	if ((sblk->status_tag != tp->last_tag) ||

	    !(tr32(TG3PCI_PCISTATE) & PCISTATE_INT_NOT_ACTIVE)) {

		/*

		 * writing any value to intr-mbox-0 clears PCI INTA# and
@@ -3362,20 +3362,17 @@ 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();

		if (tg3_irq_sync(tp))

			goto out;

		sblk->status &= ~SD_STATUS_UPDATED;

		if (likely(tg3_has_work(tp))) {

		if (netif_rx_schedule_prep(dev)) {

			prefetch(&tp->rx_rcb[tp->rx_rcb_ptr]);

			netif_rx_schedule(dev);		/* schedule NAPI poll */

		} else {

			/* no work, shared interrupt perhaps?  re-enable

			 * interrupts, and flush that PCI write

			/* Update last_tag to mark that this status has been

			 * seen. Because interrupt may be shared, we may be

			 * racing with tg3_poll(), so only update last_tag

			 * if tg3_poll() is not scheduled.

			 */

			tw32_mailbox_f(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW,

				       tp->last_tag << 24);

			tp->last_tag = sblk->status_tag;

			__netif_rx_schedule(dev);

		}

	} else {	/* shared interrupt */

		handled = 0;
@@ -6238,6 +6235,7 @@ static int tg3_test_interrupt(struct tg3 *tp) 
	if (err)

		return err;



	tp->hw_status->status &= ~SD_STATUS_UPDATED;

	tg3_enable_ints(tp);



	tw32_f(HOSTCC_MODE, tp->coalesce_mode | HOSTCC_MODE_ENABLE |