1 files changed, 13 insertions, 3 deletions

diff --git a/sound/core/timer.c b/sound/core/timer.c
index e7dc56ca4b97..7e5fe2d91662 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -44,11 +44,14 @@
 #endif
 
 static int timer_limit = DEFAULT_TIMER_LIMIT;
+static int timer_tstamp_monotonic = 1;
 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
 MODULE_DESCRIPTION("ALSA timer interface");
 MODULE_LICENSE("GPL");
 module_param(timer_limit, int, 0444);
 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
+module_param(timer_tstamp_monotonic, int, 0444);
+MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
 
 struct snd_timer_user {
         struct snd_timer_instance *timeri;
@@ -381,7 +384,10 @@ static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
         struct snd_timer_instance *ts;
         struct timespec tstamp;
 
-        getnstimeofday(&tstamp);
+        if (timer_tstamp_monotonic)
+                do_posix_clock_monotonic_gettime(&tstamp);
+        else
+                getnstimeofday(&tstamp);
         snd_assert(event >= SNDRV_TIMER_EVENT_START &&
                    event <= SNDRV_TIMER_EVENT_PAUSE, return);
         if (event == SNDRV_TIMER_EVENT_START ||
@@ -1182,8 +1188,12 @@ static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
                 spin_unlock(&tu->qlock);
                 return;
         }
-        if (tu->last_resolution != resolution || ticks > 0)
-                getnstimeofday(&tstamp);
+        if (tu->last_resolution != resolution || ticks > 0) {
+                if (timer_tstamp_monotonic)
+                        do_posix_clock_monotonic_gettime(&tstamp);
+                else
+                        getnstimeofday(&tstamp);
+        }
         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
             tu->last_resolution != resolution) {
                 r1.event = SNDRV_TIMER_EVENT_RESOLUTION;