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| author | Clemens Ladisch <clemens@ladisch.de> | 2005-08-15 10:25:24 +0400 |
|---|---|---|
| committer | Jaroslav Kysela <perex@suse.cz> | 2005-08-30 10:45:47 +0400 |
| commit | 9624ea812c7afd2e403c56366cadddb9ecfb88c6 (patch) | |
| tree | 6d48ed32f35a3b1ebb1fac0021e810f57a141e0d | |
| parent | 7efd8bc800324a967a37e8a425433468b7f06adb (diff) | |
| download | linux-9624ea812c7afd2e403c56366cadddb9ecfb88c6.tar.xz | |
[ALSA] usb-audio: actually schedule playback URBs at frame boundaries
USB generic driver
Change prepare_playback_urb() not to stop preparing packets before a
frame boundary has been reached.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
| -rw-r--r-- | sound/usb/usbaudio.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c index 2b4f916a0a9a..3f7930c0b616 100644 --- a/sound/usb/usbaudio.c +++ b/sound/usb/usbaudio.c @@ -164,6 +164,7 @@ struct snd_usb_substream { unsigned int curframesize; /* current packet size in frames (for capture) */ unsigned int fill_max: 1; /* fill max packet size always */ unsigned int fmt_type; /* USB audio format type (1-3) */ + unsigned int packs_per_ms; /* packets per millisecond (for playback) */ unsigned int running: 1; /* running status */ @@ -537,9 +538,13 @@ static int prepare_playback_urb(snd_usb_substream_t *subs, urb->iso_frame_desc[i].length = 0; urb->number_of_packets++; } + break; } - break; } + /* finish at the frame boundary at/after the period boundary */ + if (period_elapsed && + (i & (subs->packs_per_ms - 1)) == subs->packs_per_ms - 1) + break; } if (subs->hwptr_done + offs > runtime->buffer_size) { /* err, the transferred area goes over buffer boundary. */ @@ -907,6 +912,7 @@ static int init_substream_urbs(snd_usb_substream_t *subs, unsigned int period_by packs_per_ms = 8 >> subs->datainterval; else packs_per_ms = 1; + subs->packs_per_ms = packs_per_ms; if (is_playback) { urb_packs = nrpacks; |