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[TG3]: Add recovery logic when MMIOs are re-ordered

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Add recovery logic when we suspect that the system is re-ordering
MMIOs. Re-ordered MMIOs to the send mailbox can cause bogus tx
completions and hit BUG_ON() in the tx completion path.

tg3 already has logic to handle re-ordered MMIOs by flushing the MMIOs
that must be strictly ordered (such as the send mailbox).  Determining
when to enable the flush is currently a manual process of adding known
chipsets to a list.

The new code replaces the BUG_ON() in the tx completion path with the
call to tg3_tx_recover(). It will set the TG3_FLAG_MBOX_WRITE_REORDER
flag and reset the chip later in the workqueue to recover and start
flushing MMIOs to the mailbox.

A message to report the problem will be printed. We will then decide
whether or not to add the host bridge to the list of chipsets that do
re-ordering.

We may add some additional code later to print the host bridge's ID so
that the user can report it more easily.

The assumption that re-ordering can only happen on x86 systems is also
removed.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Michael Chan
2006-05-26 17:48:07 -07:00
committed by David S. Miller
parent 30b6c28d2a
commit df3e654818
2 changed files with 49 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

53
drivers/net/tg3.c
View File

@@ -2967,6 +2967,29 @@ static int tg3_setup_phy(struct tg3 *tp, int force_reset)
return err;
}
/* This is called whenever we suspect that the system chipset is re-
* ordering the sequence of MMIO to the tx send mailbox. The symptom
* is bogus tx completions. We try to recover by setting the
* TG3_FLAG_MBOX_WRITE_REORDER flag and resetting the chip later
* in the workqueue.
*/
static void tg3_tx_recover(struct tg3 *tp)
{
BUG_ON((tp->tg3_flags & TG3_FLAG_MBOX_WRITE_REORDER) ||
tp->write32_tx_mbox == tg3_write_indirect_mbox);
printk(KERN_WARNING PFX "%s: The system may be re-ordering memory-"
"mapped I/O cycles to the network device, attempting to "
"recover. Please report the problem to the driver maintainer "
"and include system chipset information.\n", tp->dev->name);
spin_lock(&tp->lock);
spin_lock(&tp->tx_lock);
tp->tg3_flags |= TG3_FLAG_TX_RECOVERY_PENDING;
spin_unlock(&tp->tx_lock);
spin_unlock(&tp->lock);
}
/* Tigon3 never reports partial packet sends. So we do not
* need special logic to handle SKBs that have not had all
* of their frags sent yet, like SunGEM does.
@@ -2979,9 +3002,13 @@ static void tg3_tx(struct tg3 *tp)
while (sw_idx != hw_idx) {
struct tx_ring_info *ri = &tp->tx_buffers[sw_idx];
struct sk_buff *skb = ri->skb;
int i;
int i, tx_bug = 0;
if (unlikely(skb == NULL)) {
tg3_tx_recover(tp);
return;
}
BUG_ON(skb == NULL);
pci_unmap_single(tp->pdev,
pci_unmap_addr(ri, mapping),
skb_headlen(skb),
@@ -2992,10 +3019,9 @@ static void tg3_tx(struct tg3 *tp)
sw_idx = NEXT_TX(sw_idx);
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
BUG_ON(sw_idx == hw_idx);
ri = &tp->tx_buffers[sw_idx];
BUG_ON(ri->skb != NULL);
if (unlikely(ri->skb != NULL || sw_idx == hw_idx))
tx_bug = 1;
pci_unmap_page(tp->pdev,
pci_unmap_addr(ri, mapping),
@@ -3006,6 +3032,11 @@ static void tg3_tx(struct tg3 *tp)
}
dev_kfree_skb(skb);
if (unlikely(tx_bug)) {
tg3_tx_recover(tp);
return;
}
}
tp->tx_cons = sw_idx;
@@ -3333,6 +3364,11 @@ static int tg3_poll(struct net_device *netdev, int *budget)
/* run TX completion thread */
if (sblk->idx[0].tx_consumer != tp->tx_cons) {
tg3_tx(tp);
if (unlikely(tp->tg3_flags & TG3_FLAG_TX_RECOVERY_PENDING)) {
netif_rx_complete(netdev);
schedule_work(&tp->reset_task);
return 0;
}
}
/* run RX thread, within the bounds set by NAPI.
@@ -3581,6 +3617,13 @@ static void tg3_reset_task(void *_data)
restart_timer = tp->tg3_flags2 & TG3_FLG2_RESTART_TIMER;
tp->tg3_flags2 &= ~TG3_FLG2_RESTART_TIMER;
if (tp->tg3_flags & TG3_FLAG_TX_RECOVERY_PENDING) {
tp->write32_tx_mbox = tg3_write32_tx_mbox;
tp->write32_rx_mbox = tg3_write_flush_reg32;
tp->tg3_flags |= TG3_FLAG_MBOX_WRITE_REORDER;
tp->tg3_flags &= ~TG3_FLAG_TX_RECOVERY_PENDING;
}
tg3_halt(tp, RESET_KIND_SHUTDOWN, 0);
tg3_init_hw(tp, 1);