From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frank Li Subject: [PATCH 1/1 v2 net] net: fec: fix kernel oops when plug/unplug cable many times Date: Sun, 28 Apr 2013 11:08:28 +0800 Message-ID: <1367118508-12340-1-git-send-email-Frank.Li@freescale.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Frank Li To: , , , , , , , Return-path: Received: from mail-db8lp0185.outbound.messaging.microsoft.com ([213.199.154.185]:23072 "EHLO db8outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750725Ab3D1Epb (ORCPT ); Sun, 28 Apr 2013 00:45:31 -0400 Sender: netdev-owner@vger.kernel.org List-ID: reproduce steps 1. flood ping from other machine ping -f -s 41000 IP 2. run below script while [ 1 ]; do ethtool -s eth0 autoneg off; sleep 3;ethtool -s eth0 autoneg on; sleep 4; done; You can see oops in one hour. The reason is fec_restart clear BD but NAPI may use it. The solution is disable NAPI and stop xmit when reset BD. disable NAPI may sleep, so fec_restart can't be call in atomic context. Signed-off-by: Frank Li --- Change from V1 to V2 Add netif_tx_lock(ndev) to avoid xmit runing when reset hardware drivers/net/ethernet/freescale/fec.c | 41 +++++++++++++++++++++++++++++----- drivers/net/ethernet/freescale/fec.h | 3 +- 2 files changed, 37 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c index 73195f6..d140b50 100644 --- a/drivers/net/ethernet/freescale/fec.c +++ b/drivers/net/ethernet/freescale/fec.c @@ -403,6 +403,12 @@ fec_restart(struct net_device *ndev, int duplex) const struct platform_device_id *id_entry = platform_get_device_id(fep->pdev); int i; + if (netif_running(ndev)) { + napi_disable(&fep->napi); + netif_stop_queue(ndev); + netif_tx_lock(ndev); + } + u32 temp_mac[2]; u32 rcntl = OPT_FRAME_SIZE | 0x04; u32 ecntl = 0x2; /* ETHEREN */ @@ -559,6 +565,12 @@ fec_restart(struct net_device *ndev, int duplex) /* Enable interrupts we wish to service */ writel(FEC_DEFAULT_IMASK, fep->hwp + FEC_IMASK); + + if (netif_running(ndev)) { + napi_enable(&fep->napi); + netif_wake_queue(ndev); + netif_tx_unlock(ndev); + } } static void @@ -598,8 +610,20 @@ fec_timeout(struct net_device *ndev) ndev->stats.tx_errors++; - fec_restart(ndev, fep->full_duplex); - netif_wake_queue(ndev); + fep->timeout = 1; + schedule_delayed_work(&fep->delay_work, msecs_to_jiffies(1)); +} + +static void fec_enet_work(struct work_struct *work) +{ + struct fec_enet_private *fep = + container_of(work, struct fec_enet_private, delay_work.work); + + if (fep->timeout) { + fep->timeout = 0; + fec_restart(fep->netdev, fep->full_duplex); + netif_wake_queue(fep->netdev); + } } static void @@ -996,9 +1020,6 @@ static void fec_enet_adjust_link(struct net_device *ndev) status_change = 1; } - /* if any of the above changed restart the FEC */ - if (status_change) - fec_restart(ndev, phy_dev->duplex); } else { if (fep->link) { fec_stop(ndev); @@ -1010,8 +1031,14 @@ static void fec_enet_adjust_link(struct net_device *ndev) spin_unlock: spin_unlock_irqrestore(&fep->hw_lock, flags); - if (status_change) + if (status_change) { + /* if any of the above changed restart the FEC, + * fec_restart may sleep. can't call it in spin_lock + */ + if (phy_dev->link) + fec_restart(ndev, phy_dev->duplex); phy_print_status(phy_dev); + } } static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum) @@ -1882,6 +1909,7 @@ fec_probe(struct platform_device *pdev) if (ret) goto failed_register; + INIT_DELAYED_WORK(&fep->delay_work, fec_enet_work); return 0; failed_register: @@ -1918,6 +1946,7 @@ fec_drv_remove(struct platform_device *pdev) struct resource *r; int i; + cancel_delayed_work_sync(&fep->delay_work); unregister_netdev(ndev); fec_enet_mii_remove(fep); del_timer_sync(&fep->time_keep); diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h index eb43729..a367b21 100644 --- a/drivers/net/ethernet/freescale/fec.h +++ b/drivers/net/ethernet/freescale/fec.h @@ -260,7 +260,8 @@ struct fec_enet_private { int hwts_rx_en; int hwts_tx_en; struct timer_list time_keep; - + struct delayed_work delay_work; + int timeout; }; void fec_ptp_init(struct net_device *ndev, struct platform_device *pdev); -- 1.7.1