usb: gadget: f_uvc: Sanity check wMaxPacketSize for SuperSpeed

As per USB3.0 Specification "Table 9-20. Standard Endpoint Descriptor",
for interrupt and isochronous endpoints, wMaxPacketSize must be set to
1024 if the endpoint defines bMaxBurst to be greater than zero.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index c7689d05356c4f57f4c7f37559a0c5d1a7fc2ec6..f8a1881609a2c808f690f6d31ea6bcaf118b8bb4 100644 (file)
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -594,6 +594,14 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
        opts->streaming_maxpacket = clamp(opts->streaming_maxpacket, 1U, 3072U);
        opts->streaming_maxburst = min(opts->streaming_maxburst, 15U);
 
+       /* For SS, wMaxPacketSize has to be 1024 if bMaxBurst is not 0 */
+       if (opts->streaming_maxburst &&
+           (opts->streaming_maxpacket % 1024) != 0) {
+               opts->streaming_maxpacket = roundup(opts->streaming_maxpacket, 1024);
+               INFO(cdev, "overriding streaming_maxpacket to %d\n",
+                    opts->streaming_maxpacket);
+       }
+
        /* Fill in the FS/HS/SS Video Streaming specific descriptors from the
         * module parameters.
         *