Re: [PATCH] net: usb: asix: ax88772_bind return error when hw_reset fail

[Marcel Ziswiler <marcel.ziswiler@toradex.com>]

On Thu, 2019-01-24 at 13:48 +0800, Zhang Run wrote:
> The ax88772_bind() should return error code immediately when the PHY
> was not reset properly through ax88772a_hw_reset().
> Otherwise, The asix_get_phyid() will block when get the PHY 
> Identifier from the PHYSID1 MII registers through asix_mdio_read() 
> due to the PHY isn't ready. Furthermore, it will produce a lot of 
> error message cause system crash.As follows:
> asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to write
>  reg index 0x0000: -71
> asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to send
>  software reset: ffffffb9
> asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to write
>  reg index 0x0000: -71
> asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to enable
>  software MII access
> asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to read
>  reg index 0x0000: -71
> asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to write
>  reg index 0x0000: -71
> asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to enable
>  software MII access
> asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to read
>  reg index 0x0000: -71
> ... 
> 
> Signed-off-by: Zhang Run <zhang.run@zte.com.cn>
> Reviewed-by: Yang Wei <yang.wei9@zte.com.cn>

Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>

> ---
>  drivers/net/usb/asix_devices.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/usb/asix_devices.c
> b/drivers/net/usb/asix_devices.c
> index b654f05..3d93993 100644
> --- a/drivers/net/usb/asix_devices.c
> +++ b/drivers/net/usb/asix_devices.c
> @@ -739,8 +739,13 @@ static int ax88772_bind(struct usbnet *dev,
> struct usb_interface *intf)
>  	asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1, &chipcode,
> 0);
>  	chipcode &= AX_CHIPCODE_MASK;
>  
> -	(chipcode == AX_AX88772_CHIPCODE) ? ax88772_hw_reset(dev, 0) :
> -					    ax88772a_hw_reset(dev, 0);
> +	ret = (chipcode == AX_AX88772_CHIPCODE) ? ax88772_hw_reset(dev,
> 0) :
> +						  ax88772a_hw_reset(dev
> , 0);
> +
> +	if (ret < 0) {
> +		netdev_dbg(dev->net, "Failed to reset AX88772: %d\n",
> ret);
> +		return ret;
> +	}
>  
>  	/* Read PHYID register *AFTER* the PHY was reset properly */
>  	phyid = asix_get_phyid(dev);