From: Joerg Roedel <joro@8bytes.org>
To: Guenter Roeck <linux@roeck-us.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"open list:INTEL IOMMU (VT-d)" <iommu@lists.linux-foundation.org>,
David Woodhouse <dwmw2@infradead.org>
Subject: Re: WARNING: at drivers/iommu/dmar.c:484 warn_invalid_dmar with Intel Motherboard
Date: Wed, 14 Aug 2013 11:36:12 +0200 [thread overview]
Message-ID: <20130814093607.GB4491@8bytes.org> (raw)
In-Reply-To: <20130709223106.GA16429@roeck-us.net>
On Tue, Jul 09, 2013 at 03:31:06PM -0700, Guenter Roeck wrote:
> On Tue, Jul 09, 2013 at 03:05:39PM -0600, Bjorn Helgaas wrote:
> > [+cc Joerg, David, iommu list]
> >
> > On Tue, Jul 9, 2013 at 2:24 PM, Guenter Roeck <linux@roeck-us.net> wrote:
> > > I started seeing this problem after updating the BIOS trying fix another issue,
> > > though I may have missed it earlier.
> > >
> > > I understand this is a BIOS bug. Would be great if someone can pass this on
> > > to Intel BIOS engineers.
> >
> > Maybe. It'd be nice if Linux handled it better, though.
> >
> If anyone has an idea how to do that, I'll be happy to write a patch.
I doubt that we can do anything meaningful here. The BIOS is broken in a
way so that we can't use the IOMMU in Linux. We can patch away the
WARN_ON and make it a sumple FW_BUG message, but the noise a WARN_ON
makes maybe help getting this issue fixed.
But I may be convinced otherwise, if people think this WARN_ON is not
worth it.
Joerg
prev parent reply other threads:[~2013-08-14 9:36 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-09 20:24 WARNING: at drivers/iommu/dmar.c:484 warn_invalid_dmar with Intel Motherboard Guenter Roeck
2013-07-09 21:05 ` Bjorn Helgaas
2013-07-09 22:31 ` Guenter Roeck
2013-07-09 23:22 ` Chris Wright
2013-07-09 23:43 ` Guenter Roeck
2013-07-10 0:05 ` Chris Wright
2013-07-10 0:18 ` Guenter Roeck
2013-07-10 0:53 ` David Woodhouse
2013-07-10 3:55 ` Guenter Roeck
2013-07-11 19:00 ` Chris Wright
2013-07-11 20:59 ` Guenter Roeck
2013-07-11 22:31 ` Chris Wright
2013-08-14 9:36 ` Joerg Roedel [this message]
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