Re: [PATCH] net: asix: fix bad header length bug

[Igor Gnatenko <i.gnatenko.brain@gmail.com>]

On Thu, 2014-02-06 at 13:56 +0100, Emil Goode wrote: 
> The AX88772B occasionally send rx packets that cross urb boundaries
> and the remaining partial packet is sent with no header.
> When the buffer with a partial packet is of less number of octets
> than the value of hard_header_len the buffer is discarded by the
> usbnet module. This is causing dropped packages and error messages
> in dmesg.
> 
> This can be reproduced by using ping with a packet size
> between 1965-1976.
> 
> The bug has been reported here:
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=29082
> 
> Signed-off-by: Emil Goode <emilgoode@gmail.com>
Reported-and-tested-by: Igor Gnatenko <i.gnatenko.brain@gmail.com> 
> ---
>  drivers/net/usb/asix_devices.c |    1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
> index 9765a7d..120bb29 100644
> --- a/drivers/net/usb/asix_devices.c
> +++ b/drivers/net/usb/asix_devices.c
> @@ -455,6 +455,7 @@ static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf)
>  	dev->net->ethtool_ops = &ax88772_ethtool_ops;
>  	dev->net->needed_headroom = 4; /* cf asix_tx_fixup() */
>  	dev->net->needed_tailroom = 4; /* cf asix_tx_fixup() */
> +	dev->net->hard_header_len = 0; /* Partial packets have no header */
>  
>  	embd_phy = ((dev->mii.phy_id & 0x1f) == 0x10 ? 1 : 0);
>  


-- 
-Igor Gnatenko