Re: [PATCH] efifb: dmi set video type

From: Huang Ying
Date: Sun Mar 22 2009 - 22:06:50 EST


Hi, Brian,

The patch is OK for me.

Please cc linux-fbdev-devel@xxxxxxxxxxxxxxxxxxxxx and "Antonino A.
Daplas" <adaplas@xxxxxxx> on framebuffer driver patches.

Best Regards,
Huang Ying

On Sun, 2009-03-22 at 06:16 +0800, Brian Maly wrote:
> 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: Brian Maly <bmaly@redhat>
>
>

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