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authorClemens Ladisch <clemens@ladisch.de>2005-05-02 08:53:46 +0200
committerJaroslav Kysela <perex@suse.cz>2005-05-29 10:05:54 +0200
commit1149a64fe4916fe6fdc8938043a0dc9a6551ab63 (patch)
treefc27fcf75435d8fb856e572018fc964382e3deb7 /sound/usb/usbaudio.c
parent4dc40a3cc4778ebcb6212bdb71b48690a153be07 (diff)
[ALSA] usb-audio - use proper interval between synchronization packets
USB generic driver Add sanity checks when reading the bRefresh value, and actually use it for the synchronization packets instead of polling at 1000 Hz. Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Diffstat (limited to 'sound/usb/usbaudio.c')
-rw-r--r--sound/usb/usbaudio.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index e759b73942c..e1a648d7fff 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -1051,10 +1051,7 @@ static int init_substream_urbs(snd_usb_substream_t *subs, unsigned int period_by
u->urb->pipe = subs->syncpipe;
u->urb->transfer_flags = URB_ISO_ASAP;
u->urb->number_of_packets = u->packets;
- if (snd_usb_get_speed(subs->dev) == USB_SPEED_HIGH)
- u->urb->interval = 8;
- else
- u->urb->interval = 1;
+ u->urb->interval = 1 << subs->syncinterval;
u->urb->context = u;
u->urb->complete = snd_usb_complete_callback(snd_complete_sync_urb);
}
@@ -1272,7 +1269,12 @@ static int set_format(snd_usb_substream_t *subs, struct audioformat *fmt)
subs->syncpipe = usb_rcvisocpipe(dev, ep);
else
subs->syncpipe = usb_sndisocpipe(dev, ep);
- subs->syncinterval = get_endpoint(alts, 1)->bRefresh;
+ if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
+ get_endpoint(alts, 1)->bRefresh >= 1 &&
+ get_endpoint(alts, 1)->bRefresh <= 9)
+ subs->syncinterval = get_endpoint(alts, 1)->bRefresh;
+ else
+ subs->syncinterval = 1;
}
/* always fill max packet size */