Re: sata suspend resume ...

[Hugh Dickins <hugh@veritas.com>]

On Wed, 19 Apr 2006, Jeff Chua wrote:
> 
> Any change of getting suspend/resume to work on my IBM X60s notebook.
> 
> Disk model is ...
> 
> 	MODEL="ATA HTS541060G9SA00"
> 	FW_REV="MB3I"
> 
> Linux 2.6.17-rc2.
> 
> System suspends ok. Resume ok. but no disk access after that.

Not the same disk model, but I've been having similar trouble on a T43p.

I was delighted to see the MSI suspend/resume fix go into 2.6.17-rc2,
but then disappointed.  A bisection found that Matt Mackall's sensible
rc1 patch, to speed up get_cmos_time, has removed what often used to be
a 2 second delay in resuming: things work well when I reinstate that
delay (1 second has proved not enough).  Below is the patch I'm using -
where I've failed to resist mucking around to avoid those double calls
to get_cmos_time, sorry: really it's just mdelay(2000) needed somewhere
(until someone who knows puts in something more scientific).

Your problem, of course, is quite likely to be something else entirely;
but I thought I ought to speak up, in case it does help.

Hugh

--- 2.6.17-rc2/arch/i386/kernel/time.c	2006-03-20 05:53:29.000000000 +0000
+++ linux/arch/i386/kernel/time.c	2006-04-19 09:56:02.000000000 +0100
@@ -379,6 +379,7 @@ void notify_arch_cmos_timer(void)
 }
 
 static long clock_cmos_diff, sleep_start;
+unsigned long resume_mdelay = 2000;
 
 static struct timer_opts *last_timer;
 static int timer_suspend(struct sys_device *dev, pm_message_t state)
@@ -386,9 +387,8 @@ static int timer_suspend(struct sys_devi
 	/*
 	 * Estimate time zone so that set_time can update the clock
 	 */
-	clock_cmos_diff = -get_cmos_time();
-	clock_cmos_diff += get_seconds();
 	sleep_start = get_cmos_time();
+	clock_cmos_diff = get_seconds() - sleep_start;
 	last_timer = cur_timer;
 	cur_timer = &timer_none;
 	if (last_timer->suspend)
@@ -407,10 +407,11 @@ static int timer_resume(struct sys_devic
 		hpet_reenable();
 #endif
 	setup_pit_timer();
-	sec = get_cmos_time() + clock_cmos_diff;
-	sleep_length = (get_cmos_time() - sleep_start) * HZ;
+	mdelay(resume_mdelay);
+	sec = get_cmos_time();
+	sleep_length = (sec - sleep_start) * HZ;
 	write_seqlock_irqsave(&xtime_lock, flags);
-	xtime.tv_sec = sec;
+	xtime.tv_sec = clock_cmos_diff + sec;
 	xtime.tv_nsec = 0;
 	jiffies_64 += sleep_length;
 	wall_jiffies += sleep_length;