On Mon, 17 Oct 2016 13:15:13 -0400 (EDT), David Miller wrote:
> From: Jakub Kicinski <kubak...@wp.pl>
> 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 <kubak...@wp.pl>
> >> 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.
Hm. I must be missing something really obvious. I just booted
net-next an hour ago and couldn't set MTU to anything larger than 1500
on either nfp or igb. As far as I can read the code it will set the
max_mtu to 1500 in setup_ether() but none of the jumbo-capable drivers
had been touched by Jarod so far...