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-rw-r--r--sound/usb/usbaudio.c29
1 files changed, 5 insertions, 24 deletions
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index f3d4de23fed..44485b29f67 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -1035,9 +1035,9 @@ static void release_substream_urbs(struct snd_usb_substream *subs, int force)
static int init_substream_urbs(struct snd_usb_substream *subs, unsigned int period_bytes,
unsigned int rate, unsigned int frame_bits)
{
- unsigned int maxsize, n, i;
+ unsigned int maxsize, i;
int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
- unsigned int npacks[MAX_URBS], urb_packs, total_packs, packs_per_ms;
+ unsigned int urb_packs, total_packs, packs_per_ms;
/* calculate the frequency in 16.16 format */
if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
@@ -1109,31 +1109,11 @@ static int init_substream_urbs(struct snd_usb_substream *subs, unsigned int peri
/* too much... */
subs->nurbs = MAX_URBS;
total_packs = MAX_URBS * urb_packs;
- }
- n = total_packs;
- for (i = 0; i < subs->nurbs; i++) {
- npacks[i] = n > urb_packs ? urb_packs : n;
- n -= urb_packs;
- }
- if (subs->nurbs <= 1) {
+ } else if (subs->nurbs < 2) {
/* too little - we need at least two packets
* to ensure contiguous playback/capture
*/
subs->nurbs = 2;
- npacks[0] = (total_packs + 1) / 2;
- npacks[1] = total_packs - npacks[0];
- } else if (npacks[subs->nurbs-1] < MIN_PACKS_URB * packs_per_ms) {
- /* the last packet is too small.. */
- if (subs->nurbs > 2) {
- /* merge to the first one */
- npacks[0] += npacks[subs->nurbs - 1];
- subs->nurbs--;
- } else {
- /* divide to two */
- subs->nurbs = 2;
- npacks[0] = (total_packs + 1) / 2;
- npacks[1] = total_packs - npacks[0];
- }
}
/* allocate and initialize data urbs */
@@ -1141,7 +1121,8 @@ static int init_substream_urbs(struct snd_usb_substream *subs, unsigned int peri
struct snd_urb_ctx *u = &subs->dataurb[i];
u->index = i;
u->subs = subs;
- u->packets = npacks[i];
+ u->packets = (i + 1) * total_packs / subs->nurbs
+ - i * total_packs / subs->nurbs;
u->buffer_size = maxsize * u->packets;
if (subs->fmt_type == USB_FORMAT_TYPE_II)
u->packets++; /* for transfer delimiter */