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author | Clemens Ladisch <clemens@ladisch.de> | 2009-08-10 10:07:35 +0200 |
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committer | Takashi Iwai <tiwai@suse.de> | 2009-08-10 13:13:56 +0200 |
commit | 765e8db078e63fdc076fcf6024c15d3b7b955746 (patch) | |
tree | 2962fb6a3f4b03cf1480c122356fed0069d3bdff /sound/usb | |
parent | sound: usb-audio: add MIDI drain callback (diff) | |
download | linux-765e8db078e63fdc076fcf6024c15d3b7b955746.tar.xz linux-765e8db078e63fdc076fcf6024c15d3b7b955746.zip |
sound: usb-audio: do not make URBs longer than sync packet interval
Using more packets in one URB do avoid interrupts does not make sense
when we have a sync pipe whose packets generate interrupts more often.
Therefore, limit the URB size to the synchronization packet interval.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb')
-rw-r--r-- | sound/usb/usbaudio.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c index 44b9cdc8a83b..fa3f7a1dc5e1 100644 --- a/sound/usb/usbaudio.c +++ b/sound/usb/usbaudio.c @@ -1083,6 +1083,8 @@ static int init_substream_urbs(struct snd_usb_substream *subs, unsigned int peri } else urb_packs = 1; urb_packs *= packs_per_ms; + if (subs->syncpipe) + urb_packs = min(urb_packs, 1 << subs->syncinterval); /* decide how many packets to be used */ if (is_playback) { |