sunvnet: Return from vnet_napi_event() if no packets to read

vnet_event_napi() may be called as part of the NAPI ->poll,
to resume reading descriptor rings. When no data is available,
descriptor ring state (e.g., rcv_nxt) needs to be reset
carefully to stay in lock-step with ldc_read(). In the interest
of simplicity, the best way to do this is to return from
vnet_event_napi() when there are no more packets to read.
The next trip through ldc_rx will correctly set up the dring state.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Tested-by: David Stevens <david.stevens@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Sowmini Varadhan 2014-11-06 14:51:08 -05:00 committed by David S. Miller
parent 6c3ce8a30c
commit 8c4ee3e706

View File

@ -691,7 +691,6 @@ ldc_ctrl:
pkt->end_idx = -1; pkt->end_idx = -1;
goto napi_resume; goto napi_resume;
} }
ldc_read:
err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf)); err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
if (unlikely(err < 0)) { if (unlikely(err < 0)) {
if (err == -ECONNRESET) if (err == -ECONNRESET)
@ -722,8 +721,8 @@ napi_resume:
err = vnet_rx(port, &msgbuf, &npkts, budget); err = vnet_rx(port, &msgbuf, &npkts, budget);
if (npkts >= budget) if (npkts >= budget)
break; break;
if (npkts == 0 && err != -ECONNRESET) if (npkts == 0)
goto ldc_read; break;
} else if (msgbuf.tag.stype == VIO_SUBTYPE_ACK) { } else if (msgbuf.tag.stype == VIO_SUBTYPE_ACK) {
err = vnet_ack(port, &msgbuf); err = vnet_ack(port, &msgbuf);
if (err > 0) if (err > 0)