Commit 8b937898 authored by Truxton Fulton's avatar Truxton Fulton Committed by Linus Torvalds

i386: fix machine rebooting

Commit 59f4e7d5 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-59f4e7d5)
code and if that doesn't work out, try the new,
post-59f4e7d5 code instead.

Cc: Lee Garrett <lee-in-berlin@web.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent bd78432c
......@@ -19,14 +19,37 @@ static inline void kb_wait(void)
static inline void mach_reboot(void)
{
int i;
/* old method, works on most machines */
for (i = 0; i < 10; i++) {
kb_wait();
udelay(50);
outb(0xfe, 0x64); /* pulse reset low */
udelay(50);
}
/* New method: sets the "System flag" which, when set, indicates
* successful completion of the keyboard controller self-test (Basic
* Assurance Test, BAT). This is needed for some machines with no
* keyboard plugged in. This read-modify-write sequence sets only the
* system flag
*/
for (i = 0; i < 10; i++) {
int cmd;
outb(0x20, 0x64); /* read Controller Command Byte */
udelay(50);
kb_wait();
udelay(50);
cmd = inb(0x60);
udelay(50);
kb_wait();
udelay(50);
outb(0x60, 0x64); /* write Controller Command Byte */
udelay(50);
kb_wait();
udelay(50);
outb(0x14, 0x60); /* set "System flag" */
outb(cmd | 0x04, 0x60); /* set "System flag" */
udelay(50);
kb_wait();
udelay(50);
......
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