diff options
| author | Divy Le Ray <divy@chelsio.com> | 2008-03-13 00:13:30 -0700 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2008-03-17 08:07:01 -0400 |
| commit | cd7e903440bad2625afa4090f34bf497593656cd (patch) | |
| tree | fd718ac8012aa60ad855556bc0caa903fe69ac4c | |
| parent | cdb346977829885cbd8b1200ca21049b1df242ad (diff) | |
cxgb3: Fix transmit queue stop mechanism
The last change in the Tx queue stop mechanism opens a window
where the Tx queue might be stopped after pending credits
returned.
Tx credits are returned via a control message generated by the HW.
It returns tx credits on demand, triggered by a completion bit
set in selective transmit packet headers.
The current code can lead to the Tx queue stopped
with all pending credits returned, and the current frame
not triggering a credit return. The Tx queue will then never be
awaken.
The driver could alternatively request a completion for packets
that stop the queue. It's however safer at this point to go back
to the pre-existing behaviour.
Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
| -rw-r--r-- | drivers/net/cxgb3/sge.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/net/cxgb3/sge.c b/drivers/net/cxgb3/sge.c index 979f3fc5e76..db586870c5f 100644 --- a/drivers/net/cxgb3/sge.c +++ b/drivers/net/cxgb3/sge.c @@ -1107,9 +1107,15 @@ int t3_eth_xmit(struct sk_buff *skb, struct net_device *dev) } q->in_use += ndesc; - if (unlikely(credits - ndesc < q->stop_thres)) - if (USE_GTS || !should_restart_tx(q)) - t3_stop_queue(dev, qs, q); + if (unlikely(credits - ndesc < q->stop_thres)) { + t3_stop_queue(dev, qs, q); + + if (should_restart_tx(q) && + test_and_clear_bit(TXQ_ETH, &qs->txq_stopped)) { + q->restarts++; + netif_wake_queue(dev); + } + } gen = q->gen; q->unacked += ndesc; |