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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>
Roger Quadros 8 years ago
parent
commit
16bb05d98c
1 changed files with 8 additions and 0 deletions
  1. 8 0
      drivers/usb/gadget/function/f_uvc.c

+ 8 - 0
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.
 	 *