Commit 5971897f authored Aug 09, 2009 by Markus Rechberger Committed by Greg Kroah-Hartman Sep 23, 2009

USB: increase usbdevfs max isoc buffer size

The current limit only allows isochronous transfers up to 32kbyte/urb,
updating this to 192 kbyte/urb improves the reliability of the
transfer. USB 2.0 transfer is possible with 32kbyte but increases the
chance of corrupted/incomplete data when the system is performing some
other tasks in the background.

http://www.spinics.net/lists/linux-usb/msg19955.html



Signed-off-by: Markus Rechberger <mrechberger@gmail.com>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

parent 7949f4e1

drivers/usb/core/devio.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1091,7 +1091,8 @@ static int proc_do_submiturb(struct dev_state ps, struct usbdevfs_urb uurb,
		}
		totlen += isopkt[u].length;
		}
		if (totlen > 32768) {
		/* 3072 * 64 microframes */
		if (totlen > 196608) {
		kfree(isopkt);
		return -EINVAL;
		}