Hi,
I had posted this to LKML and should have CC'd this list too, so instead
Im reposting to this list.
Initial post: http://lkml.org/lkml/2009/3/21/284
The current logic for dmi matching in efifb does not allow efifb to load
on all hardware that we can dmi match for. We should trust a dmi match
and set video type too if we dont already have one passed in from the
bootloader. Currently this info needs to be set by the bootloader just
to proceed to looking for a dmi match.
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 too. Many bootloaders fail to set screen
info on Apple hardware, and this is a big problem for people who want to
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: Brian Maly <redacted>
efifb.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)