From b1c86bb807448701400abc6eb8e958475ab5424b Mon Sep 17 00:00:00 2001
From: Clemens Ladisch <clemens@ladisch.de>
Date: Mon, 2 Mar 2009 12:06:28 +0100
Subject: [PATCH] sound: usb-audio: fix queue length check for high speed
devices
When checking for the maximum queue length, we have to take into account
that MAX_QUEUE is measured in milliseconds (i.e., frames) while the unit
of urb_packs is whatever data packet interval the device uses (possibly
less than one frame when using high speed devices).
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/usb/usbaudio.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index f853b627cf43..defe9913cbb2 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -1095,9 +1095,8 @@ static int init_substream_urbs(struct snd_usb_substream *subs, unsigned int peri
total_packs = 2 * packs_per_ms;
} else {
/* and we don't want too long a queue either */
- maxpacks = max((unsigned int)MAX_QUEUE, urb_packs * 2);
- if (total_packs > maxpacks * packs_per_ms)
- total_packs = maxpacks * packs_per_ms;
+ maxpacks = max(MAX_QUEUE * packs_per_ms, urb_packs * 2);
+ total_packs = min(total_packs, maxpacks);
}
} else {
total_packs = MAX_URBS * urb_packs;