Re: [PATCH] CDC_NCM adding support IFF_NOARP for infineon modem platform

On Sat, 2013-01-12 at 15:35 -0800, David Miller wrote:

From: Wei Shuai <redacted>
Date: Sat, 12 Jan 2013 19:34:39 +0800

quoted

Infineon(now Intel) HSPA Modem platform NCM cannot support ARP. so I
introduce a flag CDC_NCM_DRIVER_DATA_NOARP which is defined in
driver_info:data. so later on, if more such buggy devices are found,
they could use same flag to handle.

Is it no able to do ARP or, the more likely case, does broadcast
not work at all?

If it's the latter, IFF_NOARP is just making over the real problem.

I'm not applying this, no hardware device should set IFF_NOARP.
You probably really want IFF_POINTOPOINT or similar.

IFF_NOARP is already done for other WWAN devices (sierra_net, hso,
cdc-ether, cdc-phonet, lg-vl600, etc) so there is some precedent.  Some
drivers (phonet, hso) set *both* POINTTOPOINT and NOARP.  Is that
redundant, and should all WWAN drivers be moved to only POINTTOPOINT?

(aside: usbnet has FLAG_POINTTOPOINT, but that's nothing to do with
IFF_POINTTOPOINT, it only controls whether the interface is named usbX
or ethX.  Confusing.)

Dan