diff options
author | H. Peter Anvin <hpa@zytor.com> | 2010-02-19 16:21:38 -0500 |
---|---|---|
committer | H. Peter Anvin <hpa@zytor.com> | 2010-02-19 16:21:38 -0500 |
commit | 8e92dc767abb58357e696a48fc3d8ce615a9c01a (patch) | |
tree | 5e36758eb4f4bdf57be5d63255b1c82bb9a945e6 | |
parent | eb572a5c7951288e265b3e8f9a5d37b6abb2e996 (diff) |
x86, setup: Don't skip mode setting for the standard VGA modes
The code for setting standard VGA modes probes for the current mode,
and skips the mode setting if the mode is 3 (color text 80x25) or 7
(mono text 80x25). Unfortunately, there are BIOSes, including the
VMware BIOS, which report the previous mode if function 0F is queried
while the screen is in a VESA mode, and of course, nothing can help a
mode poked directly into the hardware.
As such, the safe option is to set the mode anyway, and only query to
see if we should be using mode 7 rather than mode 3. People who don't
want any mode setting at all should probably use vga=0x0f04
(VIDEO_CURRENT_MODE). It's possible that should be the kernel
default.
Reported-by Rene Arends <R.R.Arends@hro.nl>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <tip-*@git.kernel.org>
-rw-r--r-- | arch/x86/boot/video-vga.c | 9 |
1 files changed, 1 insertions, 8 deletions
diff --git a/arch/x86/boot/video-vga.c b/arch/x86/boot/video-vga.c index 819caa1f2008..ed7aeff786b2 100644 --- a/arch/x86/boot/video-vga.c +++ b/arch/x86/boot/video-vga.c | |||
@@ -42,22 +42,15 @@ static u8 vga_set_basic_mode(void) | |||
42 | { | 42 | { |
43 | struct biosregs ireg, oreg; | 43 | struct biosregs ireg, oreg; |
44 | u16 ax; | 44 | u16 ax; |
45 | u8 rows; | ||
46 | u8 mode; | 45 | u8 mode; |
47 | 46 | ||
48 | initregs(&ireg); | 47 | initregs(&ireg); |
49 | 48 | ||
49 | /* Query current mode */ | ||
50 | ax = 0x0f00; | 50 | ax = 0x0f00; |
51 | intcall(0x10, &ireg, &oreg); | 51 | intcall(0x10, &ireg, &oreg); |
52 | mode = oreg.al; | 52 | mode = oreg.al; |
53 | 53 | ||
54 | set_fs(0); | ||
55 | rows = rdfs8(0x484); /* rows minus one */ | ||
56 | |||
57 | if ((oreg.ax == 0x5003 || oreg.ax == 0x5007) && | ||
58 | (rows == 0 || rows == 24)) | ||
59 | return mode; | ||
60 | |||
61 | if (mode != 3 && mode != 7) | 54 | if (mode != 3 && mode != 7) |
62 | mode = 3; | 55 | mode = 3; |
63 | 56 | ||