Re: [tip:x86/urgent] x86: Fix boot on Twinhead H12Y

["H. Peter Anvin" <hpa@zytor.com>]

On 05/17/2012 11:22 AM, tip-bot for Alan Cox wrote:
> Commit-ID:  80b3e557371205566a71e569fbfcce5b11f92dbe
> Gitweb:     http://git.kernel.org/tip/80b3e557371205566a71e569fbfcce5b11f92dbe
> Author:     Alan Cox <alan@linux.intel.com>
> AuthorDate: Tue, 15 May 2012 18:44:15 +0100
> Committer:  Ingo Molnar <mingo@kernel.org>
> CommitDate: Thu, 17 May 2012 20:04:00 +0200
> 
> x86: Fix boot on Twinhead H12Y
> 
> Despite lots of investigation into why this is needed we don't
> know or have an elegant cure. The only answer found on this
> laptop is to mark a problem region as used so that Linux doesn't
> put anything there.
> 
> Currently all the users add reserve= command lines and anyone
> not knowing this needs to find the magic page that documents it.
> Automate it instead.
> 
> Signed-off-by: Alan Cox <alan@linux.intel.com>
> Tested-and-bugfixed-by: Arne Fitzenreiter <arne@fitzenreiter.de>
> Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=10231
> Link: http://lkml.kernel.org/r/20120515174347.5109.94551.stgit@bluebook
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> ---
>  arch/x86/pci/fixup.c |   17 +++++++++++++++++
>  1 files changed, 17 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
> index d0e6e40..5dd467b 100644
> --- a/arch/x86/pci/fixup.c
> +++ b/arch/x86/pci/fixup.c
> @@ -519,3 +519,20 @@ static void sb600_disable_hpet_bar(struct pci_dev *dev)
>  	}
>  }
>  DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_ATI, 0x4385, sb600_disable_hpet_bar);
> +
> +/*
> + * Twinhead H12Y needs us to block out a region otherwise we map devices
> + * there and any access kills the box.
> + *
> + *   See: https://bugzilla.kernel.org/show_bug.cgi?id=10231
> + *
> + * Match off the LPC and svid/sdid (older kernels lose the bridge subvendor)
> + */
> +static void __devinit twinhead_reserve_killing_zone(struct pci_dev *dev)
> +{
> +        if (dev->subsystem_vendor == 0x14FF && dev->subsystem_device == 0xA003) {
> +                pr_info("Reserving memory on Twinhead H12Y\n");
> +                request_mem_region(0xFFB00000, 0x100000, "twinhead");
> +        }
> +}
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x27B9, twinhead_reserve_killing_zone);

It seems to me that a DMI match might be more appropriate, since it
pretty much sounds like the BIOS fails to reserve a region it is using?

	-hpa