Re: suspend/resume support for PIT (time.c)

[Andrew Morton <akpm@osdl.org>]

Pavel Machek <pavel@ucw.cz> wrote:
>
> > As none of this really has anything to do w/ the PIT, and to avoid
> > confusion w/ the PIT timesource code, could we rename this to
> > "time_suspend" and "time_resume"?
> 
> Applied, altrough I'll not try to push it for a while. (I'm not sure
> if Andrew applied previous patches and do not want to clash).

I already converted the patch.    Here's what I currently have:




From: Pavel Machek <pavel@ucw.cz>

This adds proper suspend/resume support for PIT.  That means that clock are
actually correct after suspend/resume.


---

 25-akpm/arch/i386/kernel/time.c |   24 ++++++++++++++++++++++++
 1 files changed, 24 insertions(+)

diff -puN arch/i386/kernel/time.c~suspend-resume-for-PIT arch/i386/kernel/time.c
--- 25/arch/i386/kernel/time.c~suspend-resume-for-PIT	Mon Jan 12 13:49:55 2004
+++ 25-akpm/arch/i386/kernel/time.c	Mon Jan 12 13:49:55 2004
@@ -307,7 +307,31 @@ unsigned long get_cmos_time(void)
 	return retval;
 }
 
+static long clock_cmos_diff;
+
+static int time_suspend(struct sys_device *dev, u32 state)
+{
+	/*
+	 * Estimate time zone so that set_time can update the clock
+	 */
+	clock_cmos_diff = -get_cmos_time();
+	clock_cmos_diff += get_seconds();
+	return 0;
+}
+
+static int time_resume(struct sys_device *dev)
+{
+	unsigned long sec = get_cmos_time() + clock_cmos_diff;
+	write_seqlock_irq(&xtime_lock);
+	xtime.tv_sec = sec;
+	xtime.tv_nsec = 0;
+	write_sequnlock_irq(&xtime_lock);
+	return 0;
+}
+
 static struct sysdev_class pit_sysclass = {
+	.resume = time_resume,
+	.suspend = time_suspend,
 	set_kset_name("pit"),
 };
 

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