diff options
Diffstat (limited to 'sound/usb/usbaudio.c')
| -rw-r--r-- | sound/usb/usbaudio.c | 29 |
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 */ |