Commit b1c86bb8 authored Mar 02, 2009 by Clemens Ladisch Committed by Takashi Iwai Mar 02, 2009

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>

parent eab2b553

sound/usb/usbaudio.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -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;