net: usb: cdc_ncm: add support IFF_NOARP

net: usb: cdc_ncm: add support IFF_NOARP

[Wei Shuai]

Hi Alexey,
	Recently I met a Modem which cannot do ARP. But I found our
cdc_ncm_bind() function cannot handle this special case. Do you have any
plan to handle it?


static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
{
	...
 	/*  cannot do ARP */
 	dev->net->flags |= IFF_NOARP;
	...
}

Re: net: usb: cdc_ncm: add support IFF_NOARP

[Alexey Orishko]

Hi,

On Tue, Jan 8, 2013 at 2:14 PM, Wei Shuai <cpuwolf-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> Hi Alexey,
>         Recently I met a Modem which cannot do ARP. But I found our
> cdc_ncm_bind() function cannot handle this special case. Do you have any
> plan to handle it?
>
>
> static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
> {
>         ...
>         /*  cannot do ARP */
>         dev->net->flags |= IFF_NOARP;
>         ...
> }

All devices I have can handle ARP, so there was no need for such a
feature in the driver..

Last version of the driver also supports MBIM devices, which have no
MAC address at all
since payload is a pure IP, While considering changes this shall be
taken into account.

There is no way to find out if ARP is supported or not by looking at
CDC Ethernet
Networking or NCM Functional Descriptors. If control that flag to be
added to the driver,
it shall be based on matching VID/PID.

Regards,
Alexey
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Re: net: usb: cdc_ncm: add support IFF_NOARP

[Bjørn Mork]

Wei Shuai <cpuwolf@gmail.com> wrote:

>Hi Alexey,
>	Recently I met a Modem which cannot do ARP. But I found our
>cdc_ncm_bind() function cannot handle this special case. Do you have
>any
>plan to handle it?
>
>
>static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
>{
>	...
> 	/*  cannot do ARP */
> 	dev->net->flags |= IFF_NOARP;
>	...
>}
>
>--
>To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html

Are you sure all CDC NCM devices will handle this? Maybe the buggy device need a device specific quirk instead? 


Bjørn