• Brian Maly's avatar
    efifb: dmi set video type · e14a685d
    Brian Maly authored
    The current logic for dmi matching in efifb does not allow efifb to load
    on all hardware that we can dmi match for.
    
    For a real world example, boot with elilo (3.7 or 3.8 vanilla) and on a
    Apple (MacBook) and EFI framebuffer driver will not load (you will have no
    video).  This specific hardware is efi v1.10, so we have UGA and not GOP.
    Without special bootloader magic (i.e.  extra elilo patches for UGA
    graphics detection) no screen info will be passed to the kernel and as a
    result efifb will not load.
    
    This patch allows the dmi match to happen by moving it to earlier in
    efifb_init, and sets the video type (in set_system) so that efifb can load
    when we have a valid dmi match and already know the specifics of the
    hardware.
    
    Without this patch the efifb driver will fail to load in the event screen
    info is not found and passed in by the bootloader, being that we will
    never get to look for a dmi match.  A primary reason for matching with dmi
    is because not all bootloaders detect the video info properly.  The
    solution is that in the event of a dmi match, we should set
    screen_info.orig_video_isVGA.  Most bootloaders fail to set screen info on
    Apple hardware, and this is a big problem for people who use Apple
    hardware.
    
    Tested on a MacBook SantaRosa with elilo-3.8 (vanilla) and resolves the
    issue, the dmi match now works, EFI framebuffer now loads and video works.
    Signed-off-by: default avatarBrian Maly <bmaly@redhat.com>
    Acked-by: default avatarHuang Ying <ying.huang@intel.com>
    Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
    Cc: Chandramouli Narayanan <mouli@linux.intel.com>
    Acked-by: default avatarPeter Jones <pjones@redhat.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    e14a685d
efifb.c 12.3 KB