Re: ioremap_uc() followed by set_memory_wc() - burrying MTRR

Luis R. Rodriguez
2015-04-22T19:14:04Z

On Wed, Apr 22, 2015 at 12:10 PM, Doug Ledford <dledford@redhat.com> wrote:
> On Wed, 2015-04-22 at 21:05 +0200, Luis R. Rodriguez wrote:
>
>> > > I'd also love to remove the driver if it turns out there are actually
>> > > no users. qib substantially replaces it except for a few very old
>> > > cards.
>> >
>> > To be precise, the split is that ipath powers the old HTX bus cards that
>> > only work in AMD systems,
>>
>> Do those systems have PAT support? CAn anyone check if PAT is enabled
>> if booted on a recent kernel?
>
> I don't have one of these systems any more. The *only* one I ever had
> was a monster IBM box...I can't even find a reference to it any more.

Um, yeah if its so rare then I think the compromise proposed might
make sense, specially since folks were even *considering* seriously
removing this device driver. I'll send some patches to propose the
strategy explained to require booting with pat disabled.

Luis