Re: [PATCH net,stable-3.8] net: cdc_ncm, cdc_mbim: allow user to prefer NCM for backwards compatibility

[David Miller <davem@davemloft.net>]

From: Bjørn Mork <bjorn@mork.no>
Date: Thu, 14 Mar 2013 12:05:13 +0100

> commit bd329e1 ("net: cdc_ncm: do not bind to NCM compatible MBIM devices")
> introduced a new policy, preferring MBIM for dual NCM/MBIM functions if
> the cdc_mbim driver was enabled.  This caused a regression for users
> wanting to use NCM.
> 
> Devices implementing NCM backwards compatibility according to section
> 3.2 of the MBIM v1.0 specification allow either NCM or MBIM on a single
> USB function, using different altsettings.  The cdc_ncm and cdc_mbim
> drivers will both probe such functions, and must agree on a common
> policy for selecting either MBIM or NCM.  Until now, this policy has
> been set at build time based on CONFIG_USB_NET_CDC_MBIM.
> 
> Use a module parameter to set the system policy at runtime, allowing the
> user to prefer NCM on systems with the cdc_mbim driver.
> 
> Cc: Greg Suarez <gsuarez@smithmicro.com>
> Cc: Alexey Orishko <alexey.orishko@stericsson.com>
> Reported-by: Geir Haatveit <nospam@haatveit.nu>
> Reported-by: Tommi Kyntola <kynde@ts.ray.fi>
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=54791
> Signed-off-by: Bjørn Mork <bjorn@mork.no>

Ok, this is fine as a solution for now, applied and queued up for -stable.