Re: Problems Building Bluetooth with K6 and CONFIG_REGPARM

[Horms <horms@verge.net.au>]

On Thu, Sep 08, 2005 at 12:49:17PM -0400, Brian Gerst wrote:
> Horms wrote:
> >Hi Andy,
> >
> >that does indeed seem to be a problem. I have narrowed it down to
> >a combination of using K6 and CONFIG_REGPARM. Hunting around a bit
> >I found this http://my.execpc.com/~geezer/osd/gotchas/, which
> >suggests the problem is that the asm in question tries to add a register
> >to the clobber list which is not available. This makes sense,
> >I guess REGPARM is using edx, so inline assembly can't.
> >
> >I've CCed the bluetooth maintainers and lkml, hopefully someone there
> >will have some input on how to resolve this problem, as inline assembly
> >isn't my strong point and the problem seems to manifest in Linus' current
> >git tree. 
> >
> >The relevant code is the following call to BUILDIO(b,b,char) towards the
> >bottom of include/asm/io.h
> >
> >BUILDIO is as follows, and I am guessing it is the "Nd"(port) and
> >possibley "d"(port) portions that are problematic.
> 
> Sounds like a compiler bug, especially since changing the CPU type fixes 
> it.  What version of GCC?

I definately think it is compiler related, 
I was using Debian's GCC 4.0.1-6. I could try 
with 3.3 or soemthing like that if you like.

The problem was easily reproducable with
4.0.1 and a K6+CONFIG_REGPARM config.

-- 
Horms