[PATCH] Re: time() glitch on 2.4.18: solved

[Jim Paris]

> > Any comments?
> 
> Have a play with it, if your idea works when you deliberately disturb it
> then send in a patch

This works well.

-jim

diff -urN linux-2.4.18/arch/i386/kernel/time.c linux-2.4.18-jim/arch/i386/kernel/time.c
--- linux-2.4.18/arch/i386/kernel/time.c	Fri Mar 15 18:28:53 2002
+++ linux-2.4.18-jim/arch/i386/kernel/time.c	Tue Nov  5 11:22:02 2002
@@ -501,6 +501,16 @@
 
 		count = inb_p(0x40);    /* read the latched count */
 		count |= inb(0x40) << 8;
+
+		/* Any unpaired read will cause the above to swap MSB/LSB
+		   forever.  Try to detect this and reset the counter. */
+		if (count > LATCH) {
+			outb_p(0x34, 0x43);
+			outb_p(LATCH & 0xff, 0x40);
+			outb(LATCH >> 8, 0x40);
+			count = LATCH - 1;
+		}
+
 		spin_unlock(&i8253_lock);
 
 		count = ((LATCH-1) - count) * TICK_SIZE;