From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anton Vorontsov Subject: Re: [PATCH 1/3] ucc_geth: Fix empty TX queue processing Date: Mon, 11 Jan 2010 13:52:48 +0300 Message-ID: <20100111105248.GA28580@oksana.dev.rtsoft.ru> References: <0A1FE637C2C7E148B9573BB60CC630E56C3E90@zch01exm26.fsl.freescale.net> <100CB1A1877FF245BDB7AF83A0E73FFE26BE4D@zch01exm28.fsl.freescale.net> Reply-To: avorontsov@ru.mvista.com Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: linuxppc-dev@ozlabs.org, netdev@vger.kernel.org, lsorense@csclub.uwaterloo.ca, davem@davemloft.net To: Wu Jiajun-B06378 Return-path: Received: from mail.dev.rtsoft.ru ([213.79.90.226]:51113 "HELO mail.dev.rtsoft.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751247Ab0AKKwz (ORCPT ); Mon, 11 Jan 2010 05:52:55 -0500 Content-Disposition: inline In-Reply-To: <100CB1A1877FF245BDB7AF83A0E73FFE26BE4D@zch01exm28.fsl.freescale.net> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Jan 11, 2010 at 11:47:37AM +0800, Wu Jiajun-B06378 wrote: > > 'bd == ugeth->txBd[txQ]' has two possible statuses: 1)full queue. > 2)empty queue. > Removing 'netif_queue_stopped() == 0' will make transmitting stopping > when the queue is full. > > I made a new patch for this oops. [...] > + if ((bd == ugeth->txBd[txQ]) && (skb == NULL)) > break; Hm. I wonder why do we need the 'bd == ugeth->txBd[txQ]' check at all? The null skb will cause a kernel oops anyway. I think the patch below should be sufficient for the fix. Can you try it? Or if you tell me how to reproduce the issue you observe, I can try it myself. Thanks a lot! diff --git a/drivers/net/ucc_geth.c b/drivers/net/ucc_geth.c index 41ad2f3..a1a6d06 100644 --- a/drivers/net/ucc_geth.c +++ b/drivers/net/ucc_geth.c @@ -3279,13 +3279,12 @@ static int ucc_geth_tx(struct net_device *dev, u8 txQ) /* Handle the transmitted buffer and release */ /* the BD to be used with the current frame */ - if (bd == ugeth->txBd[txQ]) /* queue empty? */ + skb = ugeth->tx_skbuff[txQ][ugeth->skb_dirtytx[txQ]]; + if (!skb) break; dev->stats.tx_packets++; - skb = ugeth->tx_skbuff[txQ][ugeth->skb_dirtytx[txQ]]; - if (skb_queue_len(&ugeth->rx_recycle) < RX_BD_RING_LEN && skb_recycle_check(skb, ugeth->ug_info->uf_info.max_rx_buf_length +