On Sunday 11 October 2009 03:17:16 pm Yinghai Lu wrote: > for > > http://bugzilla.kernel.org/show_bug.cgi?id=13940 > > some system when acpi are enabled, acpi clears some BAR for some devices without > reason, and kernel will need to allocate devices for them. "ACPI clears some BARs"? I'm dubious. The handoff state is the same whether we boot with "acpi=off" or not, so the BIOS can't be clearing them. I really don't think the ACPI code in Linux clears BARs. The Linux PCI code might be clearing BARs, but it sure would be nice to know exactly why. Did you ever figure that out? > try to increase alignment to get more safe range for unassigned devices. > > Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> > > --- > arch/x86/kernel/e820.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > Index: linux-2.6/arch/x86/kernel/e820.c > =================================================================== > --- linux-2.6.orig/arch/x86/kernel/e820.c > +++ linux-2.6/arch/x86/kernel/e820.c > @@ -1378,8 +1378,8 @@ static unsigned long ram_alignment(resou > if (mb < 16) > return 1024*1024; > > - /* To 32MB for anything above that */ > - return 32*1024*1024; > + /* To 64MB for anything above that */ > + return 64*1024*1024; How do we know 64MB is the correct alignment? This feels like a hack that accidentally covers up the problem. I don't think we understand what's happening well enough. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html