ALSA: timer: Reject user params with too small ticks

[pandora-kernel.git] / sound / core / timer.c

diff --git a/sound/core/timer.c b/sound/core/timer.c
index 5628b65..87edf12 100644 (file)
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -1669,9 +1669,21 @@ static int snd_timer_user_params(struct file *file,
                return -EBADFD;
        if (copy_from_user(&params, _params, sizeof(params)))
                return -EFAULT;
-       if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
-               err = -EINVAL;
-               goto _end;
+       if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
+               u64 resolution;
+
+               if (params.ticks < 1) {
+                       err = -EINVAL;
+                       goto _end;
+               }
+
+               /* Don't allow resolution less than 1ms */
+               resolution = snd_timer_resolution(tu->timeri);
+               resolution *= params.ticks;
+               if (resolution < 1000000) {
+                       err = -EINVAL;
+                       goto _end;
+               }
        }
        if (params.queue_size > 0 &&
            (params.queue_size < 32 || params.queue_size > 1024)) {