'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. >From 726765194352d01dc8ea672d97612589b67cec3f Mon Sep 17 00:00:00 2001 From: Jiajun Wu <b06...@freescale.com> Date: Mon, 11 Jan 2010 10:57:22 +0800 Subject: [PATCH] ucc_geth: Fix empty TX queue processing Signed-off-by: Jiajun Wu <b06...@freescale.com> --- drivers/net/ucc_geth.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/ucc_geth.c b/drivers/net/ucc_geth.c index f982220..34345f0 100644 --- a/drivers/net/ucc_geth.c +++ b/drivers/net/ucc_geth.c @@ -3576,17 +3576,17 @@ static int ucc_geth_tx(struct net_device *dev, u8 txQ) while ((bd_status & T_R) == 0) { struct sk_buff *skb; + skb = ugeth->tx_skbuff[txQ][ugeth->skb_dirtytx[txQ]]; + /* BD contains already transmitted buffer. */ /* Handle the transmitted buffer and release */ /* the BD to be used with the current frame */ - if ((bd == ugeth->txBd[txQ]) && (netif_queue_stopped(dev) == 0)) + if ((bd == ugeth->txBd[txQ]) && (skb == NULL)) 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 + -- 1.5.6.3 -----Original Message----- From: linuxppc-dev-bounces+b13201=freescale....@lists.ozlabs.org [mailto:linuxppc-dev-bounces+b13201=freescale....@lists.ozlabs.org] On Behalf Of Anton Vorontsov Sent: Thursday, December 24, 2009 11:31 PM To: David Miller Cc: linuxppc-...@ozlabs.org; net...@vger.kernel.org; Lennart Sorensen Subject: [PATCH 1/3] ucc_geth: Fix empty TX queue processing ----------- Following oops was seen with the ucc_geth driver: Unable to handle kernel paging request for data at address 0x00000058 Faulting instruction address: 0xc024f2fc Oops: Kernel access of bad area, sig: 11 [#1] [...] NIP [c024f2fc] skb_recycle_check+0x14/0x100 LR [e30aa0a4] ucc_geth_poll+0xd8/0x4e0 [ucc_geth_driver] Call Trace: [df857d50] [c000b03c] __ipipe_grab_irq+0x3c/0xa4 (unreliable) [df857d60] [e30aa0a4] ucc_geth_poll+0xd8/0x4e0 [ucc_geth_driver] [df857dd0] [c0258cf8] net_rx_action+0xf8/0x1b8 [df857e10] [c0032a38] __do_softirq+0xb8/0x13c [df857e60] [c00065cc] do_softirq+0xa0/0xac [...] This is because ucc_geth_tx() tries to process an empty queue when queues are logically stopped. Stopping the queues doesn't disable polling, and since nowadays ucc_geth_tx() is actually called from the polling routine, the oops above might pop up. Fix this by removing 'netif_queue_stopped() == 0' check. Reported-by: Lennart Sorensen <lsore...@csclub.uwaterloo.ca> Signed-off-by: Anton Vorontsov <avoront...@ru.mvista.com> Tested-by: Lennart Sorensen <lsore...@csclub.uwaterloo.ca> Cc: Stable <sta...@vger.kernel.org> [2.6.32] --- drivers/net/ucc_geth.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/net/ucc_geth.c b/drivers/net/ucc_geth.c index afaf088..0f8c99e 100644 --- a/drivers/net/ucc_geth.c +++ b/drivers/net/ucc_geth.c @@ -3273,7 +3273,7 @@ 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]) && (netif_queue_stopped(dev) == 0)) + if (bd == ugeth->txBd[txQ]) /* queue empty? */ break; dev->stats.tx_packets++; -- 1.6.3.3 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev