Re: [PATCH V3] cdc_ncm: Add support for moving NDP to end of NCM frame

[David Miller <davem@davemloft.net>]

From: Enrico Mioso <mrkiko.rs@gmail.com>
Date: Wed,  8 Jul 2015 13:05:57 +0200

> NCM specs are not actually mandating a specific position in the frame for
> the NDP (Network Datagram Pointer). However, some Huawei devices will
> ignore our aggregates if it is not placed after the datagrams it points
> to. Add support for doing just this, in a per-device configurable way.
> While at it, update NCM subdrivers, disabling this functionality in all of
> them, except in huawei_cdc_ncm where it is enabled instead.
> We aren't making any distinction between different Huawei NCM devices,
> based on what the vendor driver does. Standard NCM devices are left
> unaffected: if they are compliant, they should be always usable, still
> stay on the safe side.
> 
> This change has been tested and working with a Huawei E3131 device (which
> works regardless of NDP position), a Huawei E3531 (also working both
> ways) and an E3372 (which mandates NDP to be after indexed datagrams).
> 
> V1->V2:
> - corrected wrong NDP acronym definition
> - fixed possible NULL pointer dereference
> - patch cleanup
> V2->V3:
> - Properly account for the NDP size when writing new packets to SKB
> 
> Signed-off-by: Enrico Mioso <mrkiko.rs@gmail.com>

Applied, thanks.