i386: fix machine rebooting
Commit 59f4e7d572980a521b7bdba74ab71b21f5995538 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>
diff --git a/include/asm-i386/mach-default/mach_reboot.h b/include/asm-i386/mach-default/mach_reboot.h
index a955e57..e23fd9f 100644
--- a/include/asm-i386/mach-default/mach_reboot.h
+++ b/include/asm-i386/mach-default/mach_reboot.h
@@ -19,14 +19,37 @@
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);