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authorZwane Mwaikambo <zwane@infradead.org>2007-04-02 06:14:12 -0400
committerAndi Kleen <andi@basil.nowhere.org>2007-04-02 06:14:12 -0400
commita369a7100da3b4f5c2269be25160653d2c7013fc (patch)
treef2215644e972ad89a93dabfd6106d4308be7d893 /arch/i386/boot
parent0fb2ebfcb5f0b1916ed5ff260ec953ef616fec7c (diff)
[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/i386/boot')
-rw-r--r--arch/i386/boot/video.S14
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/i386/boot/video.S b/arch/i386/boot/video.S
index 2c5b5cc55f79..8143c9516cb4 100644
--- a/arch/i386/boot/video.S
+++ b/arch/i386/boot/video.S
@@ -571,6 +571,16 @@ setr1: lodsw
571 jmp _m_s 571 jmp _m_s
572 572
573check_vesa: 573check_vesa:
574#ifdef CONFIG_FIRMWARE_EDID
575 leaw modelist+1024, %di
576 movw $0x4f00, %ax
577 int $0x10
578 cmpw $0x004f, %ax
579 jnz setbad
580
581 movw 4(%di), %ax
582 movw %ax, vbe_version
583#endif
574 leaw modelist+1024, %di 584 leaw modelist+1024, %di
575 subb $VIDEO_FIRST_VESA>>8, %bh 585 subb $VIDEO_FIRST_VESA>>8, %bh
576 movw %bx, %cx # Get mode information structure 586 movw %bx, %cx # Get mode information structure
@@ -1945,6 +1955,9 @@ store_edid:
1945 rep 1955 rep
1946 stosl 1956 stosl
1947 1957
1958 cmpw $0x0200, vbe_version # only do EDID on >= VBE2.0
1959 jl no_edid
1960
1948 pushw %es # save ES 1961 pushw %es # save ES
1949 xorw %di, %di # Report Capability 1962 xorw %di, %di # Report Capability
1950 pushw %di 1963 pushw %di
@@ -1987,6 +2000,7 @@ do_restore: .byte 0 # Screen contents altered during mode change
1987svga_prefix: .byte VIDEO_FIRST_BIOS>>8 # Default prefix for BIOS modes 2000svga_prefix: .byte VIDEO_FIRST_BIOS>>8 # Default prefix for BIOS modes
1988graphic_mode: .byte 0 # Graphic mode with a linear frame buffer 2001graphic_mode: .byte 0 # Graphic mode with a linear frame buffer
1989dac_size: .byte 6 # DAC bit depth 2002dac_size: .byte 6 # DAC bit depth
2003vbe_version: .word 0 # VBE bios version
1990 2004
1991# Status messages 2005# Status messages
1992keymsg: .ascii "Press <RETURN> to see video modes available, " 2006keymsg: .ascii "Press <RETURN> to see video modes available, "