Kick off the suspend sequence from the keyboard in a SWI rather than

in the hardware interrupt context (even if it is likely just an
ithread).  We don't document that suspend/resume routines are run from
such a context and some of the things that happen in those routines
aren't interrupt safe.  Since there's no real need to run from that
context, this restores assumptions that suspend routines have made.

This fixes Thierry Herbelot's 'Trying to sleep while sleeping is
prohibited' problem.

1 files changed, 13 insertions, 2 deletions

diff --git a/sys/kern/subr_power.c b/sys/kern/subr_power.c
index 7d69765..f1485e6 100644
--- a/sys/kern/subr_power.c
+++ b/sys/kern/subr_power.c
@@ -32,10 +32,20 @@ __FBSDID("$FreeBSD$");
 #include <sys/proc.h>
 
 #include <sys/power.h>
+#include <sys/taskqueue.h>
 
 static u_int		 power_pm_type	= POWER_PM_TYPE_NONE;
 static power_pm_fn_t	 power_pm_fn	= NULL;
 static void		*power_pm_arg	= NULL;
+static struct task	 power_pm_task;
+
+static void
+power_pm_deferred_fn(void *arg, int pending)
+{
+	int state = (int)arg;
+
+	power_pm_fn(POWER_CMD_SUSPEND, power_pm_arg, state);
+}
 
 int
 power_pm_register(u_int pm_type, power_pm_fn_t pm_fn, void *pm_arg)
@@ -48,6 +58,7 @@ power_pm_register(u_int pm_type, power_pm_fn_t pm_fn, void *pm_arg)
 		power_pm_fn	= pm_fn;
 		power_pm_arg	= pm_arg;
 		error = 0;
+		TASK_INIT(&power_pm_task, 0, power_pm_deferred_fn, NULL);
 	} else {
 		error = ENXIO;
 	}
@@ -72,8 +83,8 @@ power_pm_suspend(int state)
 	    state != POWER_SLEEP_STATE_SUSPEND &&
 	    state != POWER_SLEEP_STATE_HIBERNATE)
 		return;
-
-	power_pm_fn(POWER_CMD_SUSPEND, power_pm_arg, state);
+	power_pm_task.ta_context = (void *)state;
+	taskqueue_enqueue(taskqueue_swi, &power_pm_task);
 }
 
 /*