hpet vs suspend to ram

[Andriy Gapon]

On 03/05/2018 14:50, Andriy Gapon wrote:
> Thank you very much for the suggestion!
> It seems that doing that (and a little bit more[*]) helps indeed.
> 
> However there seems to be another issue.
> hpet_suspend() is called too early.  [Some] Other drivers require a working
> event timer for their suspend routines.  So after HPET is stopped the suspend
> process gets stuck.  Repeatedly pressing keyboard keys helps the process to
> finally reach the firmware suspend.  Everything is okay after resume.

Got a patch for this issue as well.
The idea is to suspend children in the reverse order (comparing to their attach
order).

--- a/sys/kern/subr_bus.c
+++ b/sys/kern/subr_bus.c
@@ -3772,15 +3772,16 @@ int
 bus_generic_suspend(device_t dev)
 {
 	int		error;
-	device_t	child, child2;
+	device_t	child;

-	TAILQ_FOREACH(child, &dev->children, link) {
+	TAILQ_FOREACH_REVERSE(child, &dev->children, device_list, link) {
 		error = BUS_SUSPEND_CHILD(dev, child);
-		if (error) {
-			for (child2 = TAILQ_FIRST(&dev->children);
-			     child2 && child2 != child;
-			     child2 = TAILQ_NEXT(child2, link))
-				BUS_RESUME_CHILD(dev, child2);
+		if (error != 0) {
+			child = TAILQ_NEXT(child, link);
+			if (child != NULL) {
+				TAILQ_FOREACH_FROM(child, &dev->children, link)
+					BUS_RESUME_CHILD(dev, child);
+			}
 			return (error);
 		}
 	}


-- 
Andriy Gapon