Re: [PATCH v3 net-next 2/2] net: deprecate eth_change_mtu, remove usage

[David Miller]

From: Jakub Kicinski <kubakici@xxxxx>
Date: Mon, 17 Oct 2016 18:00:27 +0100

> On Mon, 17 Oct 2016 12:49:54 -0400 (EDT), David Miller wrote:
>> From: Jakub Kicinski <kubakici@xxxxx>
>> Date: Mon, 17 Oct 2016 17:20:06 +0100
>> 
>> > Please correct me if I'm wrong but it seems like we are now limiting
>> > _all_ ethernet drivers to ETH_DATA_LEN in net-next.  
>> 
>> No, because the driver can increase the netdev->max_mtu value as needed.
> 
> But since almost no driver is doing that, yet, right now in net-next
> jumbo frames are not possible, no?  I thought the idea was the leave
> the value at 0 so drivers can opt-in as needed but since setup_ether()
> is initializing to 1500 now all ethernet driver get a default of
> limiting to 1500.
> 
> IOW this patch made checks which were done only in eth_change_mtu()
> mandatory for all drivers.

The conversions he made were in cases where the driver's method was doing
exactly the same thing eth_change_mtu() does not.

He strictly worked to keep the behavior identical compared to before his
changes, please read his patches carefully.