[PATCH v2] usbfs: Increase arbitrary limit for USB 3 isopkt length

[PATCH v2] usbfs: Increase arbitrary limit for USB 3 isopkt length

[Federico Manzan]

Increase the current arbitrary limit for isocronous packet size to a
value large enough to account for USB 3.0 super bandwidth streams,
bMaxBurst (0~15 allowed, 1~16 packets)
bmAttributes (bit 1:0, mult 0~2, 1~3 packets)
so the size max for one USB 3 isocronous transfer is
1024 byte * 16 * 3 = 49152 byte

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Federico Manzan <f.manzan@gmail.com>
---
Changes from v1:
  - fixed comment style
  - changed length value according to the comment

 drivers/usb/core/devio.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index caefc80..c88c4fb 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -1287,9 +1287,13 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
 			goto error;
 		}
 		for (totlen = u = 0; u < uurb->number_of_packets; u++) {
-			/* arbitrary limit,
-			 * sufficient for USB 2.0 high-bandwidth iso */
-			if (isopkt[u].length > 8192) {
+			/*
+			 * arbitrary limit need for USB 3.0
+			 * bMaxBurst (0~15 allowed, 1~16 packets)
+			 * bmAttributes (bit 1:0, mult 0~2, 1~3 packets)
+			 * sizemax: 1024 * 16 * 3 = 49152
+			 */
+			if (isopkt[u].length > 49152) {
 				ret = -EINVAL;
 				goto error;
 			}
-- 
1.7.10.4