From 5971897f3025249c0eea1987fb12efb8c65c93a4 Mon Sep 17 00:00:00 2001 From: Markus Rechberger Date: Sun, 9 Aug 2009 21:23:34 +0200 Subject: [PATCH] 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 Cc: Oliver Neukum Cc: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/devio.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index a1add776e89a..71514be8b715 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -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; } -- 2.20.1