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| author | Zwane Mwaikambo <zwane@infradead.org> | 2007-04-02 12:14:12 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2007-04-02 12:14:12 +0200 |
| commit | a369a7100da3b4f5c2269be25160653d2c7013fc (patch) | |
| tree | f2215644e972ad89a93dabfd6106d4308be7d893 /arch/x86_64 | |
| parent | 0fb2ebfcb5f0b1916ed5ff260ec953ef616fec7c (diff) | |
| download | linux-a369a7100da3b4f5c2269be25160653d2c7013fc.tar.bz2 | |
[PATCH] x86: Don't probe for DDC on VBE1.2
VBE1.2 doesn't support function 15h (DDC) resulting in a 'hang' whilst
uncompressing kernel with some video cards. Make sure we check VBE version
before fiddling around with DDC.
http://bugzilla.kernel.org/show_bug.cgi?id=1458
Opened: 2003-10-30 09:12 Last update: 2007-02-13 22:03
Much thanks to Tobias Hain for help in testing and investigating the bug.
Tested on;
i386, Chips & Technologies 65548 VESA VBE 1.2
CONFIG_VIDEO_SELECT=Y
CONFIG_FIRMWARE_EDID=Y
Untested on x86_64.
Signed-off-by: Zwane Mwaikambo <zwane@infradead.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'arch/x86_64')
| -rw-r--r-- | arch/x86_64/boot/video.S | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86_64/boot/video.S b/arch/x86_64/boot/video.S index d6ff88f35135..6090516c9c7f 100644 --- a/arch/x86_64/boot/video.S +++ b/arch/x86_64/boot/video.S @@ -571,6 +571,16 @@ setr1: lodsw jmp _m_s check_vesa: +#ifdef CONFIG_FIRMWARE_EDID + leaw modelist+1024, %di + movw $0x4f00, %ax + int $0x10 + cmpw $0x004f, %ax + jnz setbad + + movw 4(%di), %ax + movw %ax, vbe_version +#endif leaw modelist+1024, %di subb $VIDEO_FIRST_VESA>>8, %bh movw %bx, %cx # Get mode information structure @@ -1945,6 +1955,9 @@ store_edid: rep stosl + cmpw $0x0200, vbe_version # only do EDID on >= VBE2.0 + jl no_edid + pushw %es # save ES xorw %di, %di # Report Capability pushw %di @@ -1987,6 +2000,7 @@ do_restore: .byte 0 # Screen contents altered during mode change svga_prefix: .byte VIDEO_FIRST_BIOS>>8 # Default prefix for BIOS modes graphic_mode: .byte 0 # Graphic mode with a linear frame buffer dac_size: .byte 6 # DAC bit depth +vbe_version: .word 0 # VBE bios version # Status messages keymsg: .ascii "Press <RETURN> to see video modes available, " |