diff options
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/usb/usbaudio.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c index 9e38d3d1322..d28106e390c 100644 --- a/sound/usb/usbaudio.c +++ b/sound/usb/usbaudio.c @@ -938,7 +938,15 @@ static int init_substream_urbs(snd_usb_substream_t *subs, unsigned int period_by /* decide how many packets to be used */ if (is_playback) { - total_packs = (period_bytes + maxsize - 1) / maxsize; + unsigned int minsize; + /* determine how small a packet can be */ + minsize = (subs->freqn >> (16 - subs->datainterval)) + * (frame_bits >> 3); + /* with sync from device, assume it can be 25% lower */ + if (subs->syncpipe) + minsize -= minsize >> 2; + minsize = max(minsize, 1u); + total_packs = (period_bytes + minsize - 1) / minsize; if (total_packs < 2 * MIN_PACKS_URB) total_packs = 2 * MIN_PACKS_URB; } else { |