• Andi Kleen's avatar
    [PATCH] x86: Revert e820 MCFG heuristics · 11012d41
    Andi Kleen authored
    
    
    The check for the MCFG table being reserved in the e820 map was originally
    added to detect a broken BIOS in a preproduction Intel SDV. However it also
    breaks the Apple x86 Macs, which can't supply this properly, but need
    a working MCFG. With this patch they wouldn't use the MCFG and not work.
    
    After some discussion I think it's best to remove the heuristic again.
    It also failed on some other boxes (although it didn't cause much
    problems there because old style port access for PCI config space
    still works as fallback), but the preproduction SDVs can just use
    pci=nommcfg. Supporting production machines properly is more
    important.
    
    Edgar Hucek did all the debugging work.
    
    Cc: Arjan van de Ven <arjan@infradead.org>
    Cc: Edgar Hucek <hostmaster@ed-soft.at>
    Signed-off-by: default avatarAndi Kleen <ak@suse.de>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    11012d41
e820.c 17.2 KB