From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sowmini Varadhan Subject: [PATCH 2/2 net-next] sunvnet: Return from vnet_napi_event() if no packets to read Date: Thu, 6 Nov 2014 14:51:08 -0500 Message-ID: <20141106195108.GF6238@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org To: davem@davemloft.net, sowmini.varadhan@oracle.com, david.stevens@oracle.com Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:27732 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751151AbaKFTvK (ORCPT ); Thu, 6 Nov 2014 14:51:10 -0500 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: 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 Tested-by: David Stevens --- drivers/net/ethernet/sun/sunvnet.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/sun/sunvnet.c b/drivers/net/ethernet/sun/sunvnet.c index 2688b19..5c5fb59 100644 --- a/drivers/net/ethernet/sun/sunvnet.c +++ b/drivers/net/ethernet/sun/sunvnet.c @@ -691,7 +691,6 @@ ldc_ctrl: pkt->end_idx = -1; goto napi_resume; } -ldc_read: err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf)); if (unlikely(err < 0)) { if (err == -ECONNRESET) @@ -722,8 +721,8 @@ napi_resume: err = vnet_rx(port, &msgbuf, &npkts, budget); if (npkts >= budget) break; - if (npkts == 0 && err != -ECONNRESET) - goto ldc_read; + if (npkts == 0) + break; } else if (msgbuf.tag.stype == VIO_SUBTYPE_ACK) { err = vnet_ack(port, &msgbuf); if (err > 0) -- 1.8.4.2