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[ALSA] usb-audio - fix synchronization packet interval with Audigy 2 NX 

USB generic driver
When a device does not provide the bRefresh field in its audio endpoint
descriptors, use the bInterval field instead.

Furthermore, increase the number of sync URBs for better queueing.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
This commit is contained in:
Clemens Ladisch 2005-05-17 09:15:27 +02:00 committed by Jaroslav Kysela
parent d3ff42fd2b
commit 604cf49925
1 changed files with 7 additions and 2 deletions
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9
sound/usb/usbaudio.c
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@ -98,7 +98,7 @@ MODULE_PARM_DESC(async_unlink, "Use async unlink mode.");
#define MAX_PACKS 10
#define MAX_PACKS_HS (MAX_PACKS * 8) /* in high speed mode */
#define MAX_URBS 5 /* max. 20ms long packets */
#define SYNC_URBS 2 /* always two urbs for sync */
#define SYNC_URBS 4 /* always four urbs for sync */
#define MIN_PACKS_URB 1 /* minimum 1 packet per urb */
typedef struct snd_usb_substream snd_usb_substream_t;
@ -1240,8 +1240,13 @@ static int set_format(snd_usb_substream_t *subs, struct audioformat *fmt)
get_endpoint(alts, 1)->bRefresh >= 1 &&
get_endpoint(alts, 1)->bRefresh <= 9)
subs->syncinterval = get_endpoint(alts, 1)->bRefresh;
else
else if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
subs->syncinterval = 1;
else if (get_endpoint(alts, 1)->bInterval >= 1 &&
get_endpoint(alts, 1)->bInterval <= 16)
subs->syncinterval = get_endpoint(alts, 1)->bInterval - 1;
else
subs->syncinterval = 3;
}
/* always fill max packet size */