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Commit 54309fa6 authored by Frank Li's avatar Frank Li Committed by David S. Miller
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net: fec: fix kernel oops when plug/unplug cable many times 



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: default avatarFrank Li <Frank.Li@freescale.com>
Reviewed-by: default avatarLucas Stach <l.stach@pengutronix.de>
Tested-by: default avatarLucas Stach <l.stach@pengutronix.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2c006994

drivers/net/ethernet/freescale/fec.h

+6 −4
Original line number Diff line number Diff line
@@ -198,6 +198,11 @@ struct bufdesc_ex { 
#define FLAG_RX_CSUM_ENABLED	(BD_ENET_RX_ICE | BD_ENET_RX_PCR)

#define FLAG_RX_CSUM_ERROR	(BD_ENET_RX_ICE | BD_ENET_RX_PCR)



struct fec_enet_delayed_work {

	struct delayed_work delay_work;

	bool timeout;

};



/* The FEC buffer descriptors track the ring buffers.  The rx_bd_base and

 * tx_bd_base always point to the base of the buffer descriptors.  The

 * cur_rx and cur_tx point to the currently available buffer.
@@ -232,9 +237,6 @@ struct fec_enet_private { 
	/* The ring entries to be free()ed */

	struct bufdesc	*dirty_tx;



	/* hold while accessing the HW like ringbuffer for tx/rx but not MAC */

	spinlock_t hw_lock;



	struct	platform_device *pdev;



	int	opened;
@@ -269,7 +271,7 @@ struct fec_enet_private { 
	int hwts_rx_en;

	int hwts_tx_en;

	struct timer_list time_keep;



	struct fec_enet_delayed_work delay_work;

};



void fec_ptp_init(struct net_device *ndev, struct platform_device *pdev);

drivers/net/ethernet/freescale/fec_main.c

+33 −11
Original line number Diff line number Diff line
@@ -445,6 +445,13 @@ fec_restart(struct net_device *ndev, int duplex) 
	u32 rcntl = OPT_FRAME_SIZE | 0x04;

	u32 ecntl = 0x2; /* ETHEREN */



	if (netif_running(ndev)) {

		netif_device_detach(ndev);

		napi_disable(&fep->napi);

		netif_stop_queue(ndev);

		netif_tx_lock(ndev);

	}



	/* Whack a reset.  We should wait for this. */

	writel(1, fep->hwp + FEC_ECNTRL);

	udelay(10);
@@ -605,6 +612,13 @@ 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)) {

		netif_device_attach(ndev);

		napi_enable(&fep->napi);

		netif_wake_queue(ndev);

		netif_tx_unlock(ndev);

	}

}



static void
@@ -644,8 +658,22 @@ fec_timeout(struct net_device *ndev) 


	ndev->stats.tx_errors++;



	fec_restart(ndev, fep->full_duplex);

	netif_wake_queue(ndev);

	fep->delay_work.timeout = true;

	schedule_delayed_work(&(fep->delay_work.delay_work), 0);

}



static void fec_enet_work(struct work_struct *work)

{

	struct fec_enet_private *fep =

		container_of(work,

			     struct fec_enet_private,

			     delay_work.delay_work.work);



	if (fep->delay_work.timeout) {

		fep->delay_work.timeout = false;

		fec_restart(fep->netdev, fep->full_duplex);

		netif_wake_queue(fep->netdev);

	}

}



static void
@@ -1024,16 +1052,12 @@ static void fec_enet_adjust_link(struct net_device *ndev) 
{

	struct fec_enet_private *fep = netdev_priv(ndev);

	struct phy_device *phy_dev = fep->phy_dev;

	unsigned long flags;



	int status_change = 0;



	spin_lock_irqsave(&fep->hw_lock, flags);



	/* Prevent a state halted on mii error */

	if (fep->mii_timeout && phy_dev->state == PHY_HALTED) {

		phy_dev->state = PHY_RESUMING;

		goto spin_unlock;

		return;

	}



	if (phy_dev->link) {
@@ -1061,9 +1085,6 @@ static void fec_enet_adjust_link(struct net_device *ndev) 
		}

	}



spin_unlock:

	spin_unlock_irqrestore(&fep->hw_lock, flags);



	if (status_change)

		phy_print_status(phy_dev);

}
@@ -1732,7 +1753,6 @@ static int fec_enet_init(struct net_device *ndev) 
		return -ENOMEM;



	memset(cbd_base, 0, PAGE_SIZE);

	spin_lock_init(&fep->hw_lock);



	fep->netdev = ndev;
@@ -1952,6 +1972,7 @@ fec_probe(struct platform_device *pdev) 
	if (fep->bufdesc_ex && fep->ptp_clock)

		netdev_info(ndev, "registered PHC device %d\n", fep->dev_id);



	INIT_DELAYED_WORK(&(fep->delay_work.delay_work), fec_enet_work);

	return 0;



failed_register:
@@ -1984,6 +2005,7 @@ fec_drv_remove(struct platform_device *pdev) 
	struct fec_enet_private *fep = netdev_priv(ndev);

	int i;



	cancel_delayed_work_sync(&(fep->delay_work.delay_work));

	unregister_netdev(ndev);

	fec_enet_mii_remove(fep);

	del_timer_sync(&fep->time_keep);