Re: vlan panic in -CURRENT

On Feb 6, 2004, at 5:50 PM, SUZUKI Shinsuke wrote:
>
> I can reproduce the problem, and here's the trace:
> 	  if_up->if_route->in6_if_up->in6_ifattach->in6_ifattach_link
> 	->in6_update_ifa->in6_addmulti->if_addmulti->vlan_ioctl
> 	->vlan_setmulti->if_delmulti->fxp_ioctl->fxp_mc_setup
>
> The reason of this panic lies in if_fxp.c; fxp's
> ethernet-multicast-filter is configured before the initializtion of
> fxp driver.
>
> The attached ad-hoc patch fixed the problem, but IMHO much further
> considerataion is necessary; this happens when vlan is initialized
> before the initialization of its physical interface, and there might
> be a similar different bug (in other driver or in different situation).
>
> So could anyone see to it?
> #I'm afraid I cannot, because I'm not a device-driver expert...
>

Thanks a lot for tracking this down, I spent a few hours trying to 
reproduce it and couldn't before I discovered something slightly odd. 
This only seems to cause a panic if the fxp card has never been brought 
up since power on. If I "ifconfig fxp0 up" then warm-reboot, I can't 
make it crash. If I actually kill the power then try bringing up the 
vlan without bringing fxp0 up first, it will crash. That took a VERY 
long time to track down what was happening, but i've pretty much 
confirmed that's what is happening for me. Kinda strange, but I suppose 
I can understand what's happening.

-- Kevin