Re: netconsole breaks netpoll on bridge

Neil Horman
2014-06-17T11:40:22Z

On Tue, Jun 17, 2014 at 08:06:58AM +0200, Stefan Priebe - Profihost AG wrote:
> Am 16.06.2014 23:30, schrieb Francois Romieu:
> > Stefan Priebe - Profihost AG <s.priebe@profihost.ag> :
> > [...]
> >> That sounds great! Is there anything I can do or some code I can port to veth?
> >
> > You may add an empty handler for .ndo_poll_controller in drivers/net/veth.c
> > and give it a try on current kernel.
> >
> > It should not be too bad.
> >
> Why is an empty poll controller enough to fix it? This sounds a bit
> crazy to me.
>
Because the presence of a non-null poll_controller method is how we determine if
a device supports netpoll. Most devices require a ndo_poll_controller function
to simulate an interrupt for receiving packets, but virtual devices really
don't, so an empty function sufficies to get the device recognized as having
netpoll support. See tun_poll_controller as an example
Neil

>
> Greets,
> Stefan
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