lkml.org 
[lkml]   [2004]   [Aug]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC][PATCH] fix target_cpus() for summit subarch
From
Date
On Mon, 2004-08-30 at 11:03, john stultz wrote:
> On Fri, 2004-08-27 at 23:17, Martin J. Bligh wrote:
> > --john stultz <johnstul@us.ibm.com> wrote (on Friday, August 27, 2004 17:24:48 -0700):
> >
> > > I've been hunting down a bug affecting IBM x440/x445 systems where the
> > > floppy driver would get spurious interrupts and would not initialize
> > > properly.
> > >
> > > After digging James Cleverdon pointed out that target_cpus() is routing
> > > the interrupts to the clustered apic broadcast mask. This was causing
> > > multiple interrupts to show up, breaking the floppy init code.
> > >
> > > This one-liner fix simply routes interrupts to the first cpu to resolve
> > > this issue.
> >
> > I'd say that means your hardware is horribly broken ... but I guess this
> > might be a suitable workaround given we're going to reprogram them all
> > later.
>
> Ok, then my patch probably isn't correct. Let me grab James and we'll
> sit down and work this out later today.

So talking with more with James and Martin, the correct fix looks to be
Bill's suggestion of using Lowest Priority instead of Fixed for the
destination mode.

James still claims CPU_MASK_ALL (0xff) is wrong for target_cpus(), but
I'll let him make his case for that.

After some testing, I'll resend the corrected patch.

thanks
-john


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:05    [W:0.038 / U:2.640 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site