diff options
author | H. Peter Anvin <hpa@zytor.com> | 2008-05-30 17:19:03 -0700 |
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committer | H. Peter Anvin <hpa@zytor.com> | 2008-05-30 17:19:03 -0700 |
commit | 23deb06821442506615f34bd92ccd6a2422629d7 (patch) | |
tree | 5e95dba1471007a161e19844fab2d60d422f5423 /Documentation/i386/usb-legacy-support.txt | |
parent | 4039feb5bae72a5fed9ba6bc1a9cfd8dfe0a8613 (diff) |
x86: move x86-specific documentation into Documentation/x86
The current organization of the x86 documentation makes it appear as
if the "i386" documentation doesn't apply to x86-64, which is does.
Thus, move that documentation into Documentation/x86, and move the
x86-64-specific stuff into Documentation/x86/x86_64 with the eventual
goal to move stuff that isn't actually 64-bit specific back into
Documentation/x86.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'Documentation/i386/usb-legacy-support.txt')
-rw-r--r-- | Documentation/i386/usb-legacy-support.txt | 44 |
1 files changed, 0 insertions, 44 deletions
diff --git a/Documentation/i386/usb-legacy-support.txt b/Documentation/i386/usb-legacy-support.txt deleted file mode 100644 index 1894cdfc69d..00000000000 --- a/Documentation/i386/usb-legacy-support.txt +++ /dev/null @@ -1,44 +0,0 @@ -USB Legacy support -~~~~~~~~~~~~~~~~~~ - -Vojtech Pavlik <vojtech@suse.cz>, January 2004 - - -Also known as "USB Keyboard" or "USB Mouse support" in the BIOS Setup is a -feature that allows one to use the USB mouse and keyboard as if they were -their classic PS/2 counterparts. This means one can use an USB keyboard to -type in LILO for example. - -It has several drawbacks, though: - -1) On some machines, the emulated PS/2 mouse takes over even when no USB - mouse is present and a real PS/2 mouse is present. In that case the extra - features (wheel, extra buttons, touchpad mode) of the real PS/2 mouse may - not be available. - -2) If CONFIG_HIGHMEM64G is enabled, the PS/2 mouse emulation can cause - system crashes, because the SMM BIOS is not expecting to be in PAE mode. - The Intel E7505 is a typical machine where this happens. - -3) If AMD64 64-bit mode is enabled, again system crashes often happen, - because the SMM BIOS isn't expecting the CPU to be in 64-bit mode. The - BIOS manufacturers only test with Windows, and Windows doesn't do 64-bit - yet. - -Solutions: - -Problem 1) can be solved by loading the USB drivers prior to loading the -PS/2 mouse driver. Since the PS/2 mouse driver is in 2.6 compiled into -the kernel unconditionally, this means the USB drivers need to be -compiled-in, too. - -Problem 2) can currently only be solved by either disabling HIGHMEM64G -in the kernel config or USB Legacy support in the BIOS. A BIOS update -could help, but so far no such update exists. - -Problem 3) is usually fixed by a BIOS update. Check the board -manufacturers web site. If an update is not available, disable USB -Legacy support in the BIOS. If this alone doesn't help, try also adding -idle=poll on the kernel command line. The BIOS may be entering the SMM -on the HLT instruction as well. - |