1 files changed, 21 insertions, 8 deletions

diff --git a/sound/core/seq/seq_timer.c b/sound/core/seq/seq_timer.c
index b57a3c07ff6f..65b64a7c456d 100644
--- a/sound/core/seq/seq_timer.c
+++ b/sound/core/seq/seq_timer.c
@@ -34,10 +34,15 @@ extern int seq_default_timer_device;
 extern int seq_default_timer_subdevice;
 extern int seq_default_timer_resolution;
 
+/* allowed sequencer timer frequencies, in Hz */
+#define MIN_FREQUENCY           10
+#define MAX_FREQUENCY           6250
+#define DEFAULT_FREQUENCY       1000
+
 #define SKEW_BASE       0x10000 /* 16bit shift */
 
 static void snd_seq_timer_set_tick_resolution(seq_timer_tick_t *tick,
-                                              int tempo, int ppq, int nticks)
+                                              int tempo, int ppq)
 {
         if (tempo < 1000000)
                 tick->resolution = (tempo * 1000) / ppq;
@@ -51,7 +56,6 @@ static void snd_seq_timer_set_tick_resolution(seq_timer_tick_t *tick,
         }
         if (tick->resolution <= 0)
                 tick->resolution = 1;
-        tick->resolution *= nticks;
         snd_seq_timer_update_tick(tick, 0);
 }
 
@@ -100,7 +104,7 @@ void snd_seq_timer_defaults(seq_timer_t * tmr)
         /* setup defaults */
         tmr->ppq = 96;          /* 96 PPQ */
         tmr->tempo = 500000;    /* 120 BPM */
-        snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq, 1);
+        snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq);
         tmr->running = 0;
 
         tmr->type = SNDRV_SEQ_TIMER_ALSA;
@@ -183,7 +187,7 @@ int snd_seq_timer_set_tempo(seq_timer_t * tmr, int tempo)
         spin_lock_irqsave(&tmr->lock, flags);
         if ((unsigned int)tempo != tmr->tempo) {
                 tmr->tempo = tempo;
-                snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq, 1);
+                snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq);
         }
         spin_unlock_irqrestore(&tmr->lock, flags);
         return 0;
@@ -207,7 +211,7 @@ int snd_seq_timer_set_ppq(seq_timer_t * tmr, int ppq)
         }
 
         tmr->ppq = ppq;
-        snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq, 1);
+        snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq);
         spin_unlock_irqrestore(&tmr->lock, flags);
         return 0;
 }
@@ -326,17 +330,26 @@ int snd_seq_timer_stop(seq_timer_t * tmr)
 static int initialize_timer(seq_timer_t *tmr)
 {
         snd_timer_t *t;
+        unsigned long freq;
+
         t = tmr->timeri->timer;
         snd_assert(t, return -EINVAL);
 
+        freq = tmr->preferred_resolution;
+        if (!freq)
+                freq = DEFAULT_FREQUENCY;
+        else if (freq < MIN_FREQUENCY)
+                freq = MIN_FREQUENCY;
+        else if (freq > MAX_FREQUENCY)
+                freq = MAX_FREQUENCY;
+
         tmr->ticks = 1;
-        if (tmr->preferred_resolution &&
-            ! (t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
+        if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
                 unsigned long r = t->hw.resolution;
                 if (! r && t->hw.c_resolution)
                         r = t->hw.c_resolution(t);
                 if (r) {
-                        tmr->ticks = (unsigned int)(1000000000uL / (r * tmr->preferred_resolution));
+                        tmr->ticks = (unsigned int)(1000000000uL / (r * freq));
                         if (! tmr->ticks)
                                 tmr->ticks = 1;
                 }