[PATCH] netdev/fec: fix ifconfig eth0 down hang issue

[Bryan Wu]

Folks,

Can I get some ACK for this patch? Tim, I believe this time you will ack it, right?

Thanks,
-Bryan

On 04/29/2010 03:18 PM, Bryan Wu wrote:
> BugLink: http://bugs.launchpad.net/bugs/559065
>
> In fec open/close function, we need to use phy_connect and phy_disconnect
> operation before we start/stop phy. Otherwise it will cause system hang.
>
> Only call fec_enet_mii_probe() in open function, because the first open
> action will cause NULL pointer error.
>
> Signed-off-by: Bryan Wu<bryan.wu at canonical.com>
> ---
>   drivers/net/fec.c |   28 ++++++++++++++++------------
>   1 files changed, 16 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/fec.c b/drivers/net/fec.c
> index 2280373..692d3c4 100644
> --- a/drivers/net/fec.c
> +++ b/drivers/net/fec.c
> @@ -691,6 +691,8 @@ static int fec_enet_mii_probe(struct net_device *dev)
>   	struct phy_device *phy_dev = NULL;
>   	int phy_addr;
>
> +	fep->phy_dev = NULL;
> +
>   	/* find the first phy */
>   	for (phy_addr = 0; phy_addr<  PHY_MAX_ADDR; phy_addr++) {
>   		if (fep->mii_bus->phy_map[phy_addr]) {
> @@ -721,6 +723,11 @@ static int fec_enet_mii_probe(struct net_device *dev)
>   	fep->link = 0;
>   	fep->full_duplex = 0;
>
> +	printk(KERN_INFO "%s: Freescale FEC PHY driver [%s] "
> +		"(mii_bus:phy_addr=%s, irq=%d)\n", dev->name,
> +		fep->phy_dev->drv->name, dev_name(&fep->phy_dev->dev),
> +		fep->phy_dev->irq);
> +
>   	return 0;
>   }
>
> @@ -768,13 +775,8 @@ static int fec_enet_mii_init(struct platform_device *pdev)
>   	if (mdiobus_register(fep->mii_bus))
>   		goto err_out_free_mdio_irq;
>
> -	if (fec_enet_mii_probe(dev) != 0)
> -		goto err_out_unregister_bus;
> -
>   	return 0;
>
> -err_out_unregister_bus:
> -	mdiobus_unregister(fep->mii_bus);
>   err_out_free_mdio_irq:
>   	kfree(fep->mii_bus->irq);
>   err_out_free_mdiobus:
> @@ -928,7 +930,12 @@ fec_enet_open(struct net_device *dev)
>   	if (ret)
>   		return ret;
>
> -	/* schedule a link state check */
> +	/* Probe and connect to PHY when open the interface */
> +	ret = fec_enet_mii_probe(dev);
> +	if (ret) {
> +		fec_enet_free_buffers(dev);
> +		return ret;
> +	}
>   	phy_start(fep->phy_dev);
>   	netif_start_queue(dev);
>   	fep->opened = 1;
> @@ -942,10 +949,12 @@ fec_enet_close(struct net_device *dev)
>
>   	/* Don't know what to do yet. */
>   	fep->opened = 0;
> -	phy_stop(fep->phy_dev);
>   	netif_stop_queue(dev);
>   	fec_stop(dev);
>
> +	if (fep->phy_dev)
> +		phy_disconnect(fep->phy_dev);
> +
>           fec_enet_free_buffers(dev);
>   	clk_disable(fep->clk);
>
> @@ -1337,11 +1346,6 @@ fec_probe(struct platform_device *pdev)
>
>   	clk_disable(fep->clk);
>
> -	printk(KERN_INFO "%s: Freescale FEC PHY driver [%s] "
> -		"(mii_bus:phy_addr=%s, irq=%d)\n", ndev->name,
> -		fep->phy_dev->drv->name, dev_name(&fep->phy_dev->dev),
> -		fep->phy_dev->irq);
> -
>   	return 0;
>
>   failed_register: