1 files changed, 15 insertions, 3 deletions

diff --git a/drivers/media/usb/em28xx/em28xx-audio.c b/drivers/media/usb/em28xx/em28xx-audio.c
index 6c7d34600294..f6fcee3d4fb9 100644
--- a/drivers/media/usb/em28xx/em28xx-audio.c
+++ b/drivers/media/usb/em28xx/em28xx-audio.c
@@ -52,6 +52,7 @@ MODULE_PARM_DESC(debug, "activates debug info");
 
 #define EM28XX_MAX_AUDIO_BUFS           5
 #define EM28XX_MIN_AUDIO_PACKETS        64
+
 #define dprintk(fmt, arg...) do {                                       \
             if (debug)                                                  \
                 printk(KERN_INFO "em28xx-audio %s: " fmt,               \
@@ -217,15 +218,26 @@ static struct snd_pcm_hardware snd_em28xx_hw_capture = {
 
         .formats = SNDRV_PCM_FMTBIT_S16_LE,
 
-        .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_KNOT,
+        .rates = SNDRV_PCM_RATE_48000,
 
         .rate_min = 48000,
         .rate_max = 48000,
         .channels_min = 2,
         .channels_max = 2,
         .buffer_bytes_max = 62720 * 8,  /* just about the value in usbaudio.c */
-        .period_bytes_min = 64,         /* 12544/2, */
-        .period_bytes_max = 12544,
+
+
+        /*
+         * The period is 12.288 bytes. Allow a 10% of variation along its
+         * value, in order to avoid overruns/underruns due to some clock
+         * drift.
+         *
+         * FIXME: This period assumes 64 packets, and a 48000 PCM rate.
+         * Calculate it dynamically.
+         */
+        .period_bytes_min = 11059,
+        .period_bytes_max = 13516,
+
         .periods_min = 2,
         .periods_max = 98,              /* 12544, */
 };