[PATCH] Fix a bug in timer_suspend() on x86_64

[Rafael J. Wysocki]

Hi,

This patch is intended to fix a bug in timer_suspend() on x86_64 that causes 
hard lockups on suspend with swsusp and provide some optimizations.  It is 
based on the Nigel Cunningham's patches to to reduce delay in 
arch/kernel/time.c.  The patch is against 2.6.10-mm3 and 2.6.11-rc1.  Please 
consider for applying.

Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>

--- linux-2.6.10-mm3-orig/arch/x86_64/kernel/time.c	2005-01-13 
01:46:10.000000000 +0100
+++ linux-2.6.10-mm3/arch/x86_64/kernel/time.c	2005-01-13 01:32:05.000000000 
+0100
@@ -955,16 +955,19 @@
 
 __setup("report_lost_ticks", time_setup);
 
-static long clock_cmos_diff, sleep_start;
+static long clock_cmos_diff;
+static unsigned long sleep_start;
 
 static int timer_suspend(struct sys_device *dev, u32 state)
 {
 	/*
 	 * Estimate time zone so that set_time can update the clock
 	 */
-	clock_cmos_diff = -get_cmos_time();
+	long cmos_time =  get_cmos_time();
+
+	clock_cmos_diff = -cmos_time;
 	clock_cmos_diff += get_seconds();
-	sleep_start = jiffies;
+	sleep_start = cmos_time;
 	return 0;
 }
 
@@ -973,7 +976,7 @@
 	unsigned long flags;
 	unsigned long sec;
 	unsigned long ctime = get_cmos_time();
-	unsigned long sleep_length = ctime - sleep_start;
+	unsigned long sleep_length = (ctime - sleep_start) * HZ;
 
 	if (vxtime.hpet_address)
 		hpet_reenable();
@@ -983,7 +986,8 @@
 	xtime.tv_sec = sec;
 	xtime.tv_nsec = 0;
 	write_sequnlock_irqrestore(&xtime_lock,flags);
-	jiffies += sleep_length * HZ;
+	jiffies += sleep_length;
+	wall_jiffies += sleep_length;
 	return 0;
 }
 

-- 
- Would you tell me, please, which way I ought to go from here?
- That depends a good deal on where you want to get to.
		-- Lewis Carroll "Alice's Adventures in Wonderland"
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