Subject: Re: r8169: IO_PAGE_FAULT & netdev watchdog

From: Vincent Pelletier <[email-masked]>
Date: Fri, 1 Jun 2012 21:20:42 +0200

Thanks for the quick reply.

Le vendredi 01 juin 2012 14:59:49, vous avez écrit :
> Same thing if you reset and remove the pci device through sysfs then ask
> the PCI bridge to scan it again ?

I didn't try it before - but I should have, I know this.
rmmod; reset; modprobe -> doesn't work
rmmod; reset; remove; rescan -> doesn't work either (?!)

> https://bugzilla.kernel.org/show_bug.cgi?id=42899 contains similar if not
> identical IOMMU messages (this #bz is messy but it may be of intereset to
> add yourself to the Cc: list btw).

I found it a bit after my post (while watching the archives, in case someone 
replied without CC :) ). I posted on that bug as I couldn't find a way to just 
add me to bug CC.

> The r8169 bug is real but the IOMMU message seems rather useless if not
> bogus.

Just being curious, feel free to skip over my questions:
If it's bogus, could it be a mis-interpretation of its state when the error 
occurs (I don't know how CPU knows a fault happened, I guess some IRQ + some 
register contain error status, address of error, some process/context 
identifier) ? Or hardware bug ? Or MMU misconfiguration for some reason ?
If it's not bogus, would it be the sign of firmware bug (accessing some 
unpredictable memory upon certain conditions) ?

> You can apply the attached patch but it may not do much for your problem.
> The patch below could make a difference though. Does it ?

I'll try either and both. Given the poor result I got from 
reset/remove/rescan, I guess I should reboot between attempts, right ?
Should I prevent original module auto-loading at boot ? Maybe more than just 
r8169 ?

Regards,
-- 
Vincent Pelletier