[added to the stable tree] usb: gadget: f_uvc: Sanity check wMaxPacketSize for SuperSpeed

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From: Roger Quadros <rogerq@xxxxxx>

This patch has been added to the  stable tree. If you have any
objections, please let us know.

===============

[ Upstream commit 16bb05d98c904a4f6c5ce7e2d992299f794acbf2 ]

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@xxxxxxxxxxxxxxxx>
Signed-off-by: Roger Quadros <rogerq@xxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
 drivers/usb/gadget/function/f_uvc.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index 7405ce32a690..0e704a857115 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -611,6 +611,14 @@ 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.
 	 *
-- 
2.14.1




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