Subject: Re: ppc32 PIO recovery mecanism

From: Benjamin Herrenschmidt <[email-masked]>
Date: Mon, 06 Nov 2006 12:20:47 +1100

On Mon, 2006-11-06 at 09:18 +0800, David Woodhouse wrote:
> On Mon, 2006-11-06 at 11:41 +1100, Benjamin Herrenschmidt wrote:
> > On 32 bits powerpc, we currently have a mechanism where we try to
> > recover from machine checks happening on PIO operations (inb/outb/....).
> > This mecanisms has proven of dubious reliability in the past and it's my
> > understanding that we've pretty fixed all relevant legacy drivers that
> > distro typically load so that they don't muck around when they
> > shouldn't.
> > 
> > I'm currently merging 32 and 64 bits io.h and I would really like to
> > just get rid of that stuff, but I'd like your distro point of view
> > first. Is this mechanism still useful at all or not ?
> 
> Yes, I think it's still useful because there are some drivers which
> aren't update to use check_legacy_ioport() (or whatever other system)
> yet.
> 
> Not many, mind you -- but I'd like to be 100% sure before we drop it.
> Let's start by making it print with KERN_CRIT instead of KERN_DEBUG?

We should rate limit if we do that tho... Some drivers will just totally
flood you.

I'll keep it around for now.

Ben.