Subject: Re: [PATCH net-next] net: remove abuse of VLAN DEI/CFI bit

From: Stephen Hemminger <[email-masked]>
Date: Tue, 13 Dec 2016 17:21:18 -0800

On Sat,  3 Dec 2016 10:22:28 +0100 (CET)
Michał Mirosław <[email-masked]> wrote:

> This All-in-one patch removes abuse of VLAN CFI bit, so it can be passed
> intact through linux networking stack.
> 
> Signed-off-by: Michał Mirosław <[email-masked]>
> ---
> 
> Dear NetDevs
> 
> I guess this needs to be split to the prep..convert[]..finish sequence,
> but if you like it as is, then it's ready.
> 
> The biggest question is if the modified interface and vlan_present
> is the way to go. This can be changed to use vlan_proto != 0 instead
> of an extra flag bit.
> 
> As I can't test most of the driver changes, please look at them carefully.
> OVS and bridge eyes are especially welcome.
> 
> Best Regards,
> Michał Mirosław

Is the motivation to support 802.1ad Drop Eligability Indicator (DEI)?

If so then you need to be more verbose in the commit log, and lots more
work is needed. You need to rename fields and validate every place a
driver is using DEI bit to make sure it really does the right thing
on that hardware. It is not just a mechanical change.