[PATCH] suspend/resume support for PIT

From: Pavel Machek <pavel@ucw.cz>

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

diff --git a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c
index 65054ace15095fde96cb540456881a8465c9760e..2a7f59c379775b6ca6c055cddf76223614102163 100644 (file)
--- a/arch/i386/kernel/time.c
+++ b/arch/i386/kernel/time.c
@@ -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"),
 };