[v2] usb: devio: update max count of DPs per interval for ISOC

Commit Message

Chunfeng Yun (云春峰) Jan. 2, 2019, 1:33 a.m. UTC

The failure happened when I tried to send up to 96DPs per an interval
for SSP ISOC transations by libusb, this is used to verify SSP ISOC
function of USB3 GEN2 controller, so update it as 96DPs.
(refer usb3.1r1.0 section 8.12.6 Isochronous Transactions)

Signed-off-by: Chunfeng Yun <[e-mail]>
---
v2: update changelog text suggested by Greg
---
 drivers/usb/core/devio.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

Patch

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index a75bc0b8a50f..82c16210e34c 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -1564,12 +1564,10 @@  static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb
 		}
 		for (totlen = u = 0; u < number_of_packets; u++) {
 			/*
-			 * 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
+			 * arbitrary limit need for USB 3.1 Gen2
+			 * sizemax: 96 DPs at SSP, 96 * 1024 = 98304
 			 */
-			if (isopkt[u].length > 49152) {
+			if (isopkt[u].length > 98304) {
 				ret = -EINVAL;
 				goto error;
 			}