Re: [PATCH] x86/PCI: never allocate PCI space from the last 1Mbelow 4G

[Matthew Garrett]

On Mon, Nov 29, 2010 at 11:30:09AM -0700, Bjorn Helgaas wrote:
> 
> The last 1M before 4G contains the processor restart vector and usually
> the system ROM.  We don't know the actual ROM size; I chose 1M because
> that's how much Windows 7 appears to avoid.
> 
> Without this check, we can allocate PCI space that will never work.  On
> Matthew's HP 2530p, we put the Intel GTT "Flush Page" at the very last
> page, which causes a spontaneous power-off:
> 
>   pci_root PNP0A08:00: host bridge window [mem 0xfee01000-0xffffffff]
>   fffff000-ffffffff : Intel Flush Page (assigned by intel-gtt)
> 
> Reference: https://bugzilla.kernel.org/show_bug.cgi?id=23542
> Reported-by: Matthew Garrett <mjg@xxxxxxxxxx>
> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@xxxxxx>

Tested-by: Matthew Garrett <mjg@xxxxxxxxxx>

-- 
Matthew Garrett | mjg59@xxxxxxxxxxxxx
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