i386: fix machine rebooting
Commit 59f4e7d572
fixed machine rebooting
on Truxton's machine (when no keyboard was present). But it broke it on
Lee's machine.
The patch reinstates the old (pre-59f4e7d572980a521b7bdba74ab71b21f5995538)
code and if that doesn't work out, try the new,
post-59f4e7d572980a521b7bdba74ab71b21f5995538 code instead.
Cc: Lee Garrett <lee-in-berlin@web.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
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commit
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1 changed files with 24 additions and 1 deletions
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@ -19,14 +19,37 @@ static inline void kb_wait(void)
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static inline void mach_reboot(void)
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{
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int i;
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/* old method, works on most machines */
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for (i = 0; i < 10; i++) {
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kb_wait();
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udelay(50);
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outb(0xfe, 0x64); /* pulse reset low */
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udelay(50);
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}
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/* New method: sets the "System flag" which, when set, indicates
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* successful completion of the keyboard controller self-test (Basic
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* Assurance Test, BAT). This is needed for some machines with no
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* keyboard plugged in. This read-modify-write sequence sets only the
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* system flag
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*/
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for (i = 0; i < 10; i++) {
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int cmd;
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outb(0x20, 0x64); /* read Controller Command Byte */
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udelay(50);
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kb_wait();
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udelay(50);
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cmd = inb(0x60);
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udelay(50);
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kb_wait();
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udelay(50);
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outb(0x60, 0x64); /* write Controller Command Byte */
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udelay(50);
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kb_wait();
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udelay(50);
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outb(0x14, 0x60); /* set "System flag" */
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outb(cmd | 0x04, 0x60); /* set "System flag" */
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udelay(50);
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kb_wait();
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udelay(50);
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