From: Felipe Balbi <felipe.balbi@linux.intel.com>
Date: Wed, 28 Sep 2016 09:33:31 +0000 (+0300)
Subject: usb: gadget: composite: always set ep->mult to a sensible value
X-Git-Tag: v3.10.107~220
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7b1a80c8b132b2bebe9193d2a9325d1c20fe4063;p=thirdparty%2Fkernel%2Fstable.git

usb: gadget: composite: always set ep->mult to a sensible value

commit eaa496ffaaf19591fe471a36cef366146eeb9153 upstream.

ep->mult is supposed to be set to Isochronous and
Interrupt Endapoint's multiplier value. This value
is computed from different places depending on the
link speed.

If we're dealing with HighSpeed, then it's part of
bits [12:11] of wMaxPacketSize. This case wasn't
taken into consideration before.

While at that, also make sure the ep->mult defaults
to one so drivers can use it unconditionally and
assume they'll never multiply ep->maxpacket to zero.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 584e43c9748f0..00c03c743818c 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -129,7 +129,12 @@ ep_found:
 	_ep->desc = chosen_desc;
 	_ep->comp_desc = NULL;
 	_ep->maxburst = 0;
-	_ep->mult = 0;
+	_ep->mult = 1;
+
+	if (g->speed == USB_SPEED_HIGH && (usb_endpoint_xfer_isoc(_ep->desc) ||
+				usb_endpoint_xfer_int(_ep->desc)))
+		_ep->mult = ((usb_endpoint_maxp(_ep->desc) & 0x1800) >> 11) + 1;
+
 	if (!want_comp_desc)
 		return 0;
 
@@ -146,7 +151,7 @@ ep_found:
 		switch (usb_endpoint_type(_ep->desc)) {
 		case USB_ENDPOINT_XFER_ISOC:
 			/* mult: bits 1:0 of bmAttributes */
-			_ep->mult = comp_desc->bmAttributes & 0x3;
+			_ep->mult = (comp_desc->bmAttributes & 0x3) + 1;
 		case USB_ENDPOINT_XFER_BULK:
 		case USB_ENDPOINT_XFER_INT:
 			_ep->maxburst = comp_desc->bMaxBurst + 1;
diff --git a/drivers/usb/gadget/uvc_video.c b/drivers/usb/gadget/uvc_video.c
index 71e896d4c5ae4..43e8c65fd9edb 100644
--- a/drivers/usb/gadget/uvc_video.c
+++ b/drivers/usb/gadget/uvc_video.c
@@ -240,7 +240,7 @@ uvc_video_alloc_requests(struct uvc_video *video)
 
 	req_size = video->ep->maxpacket
 		 * max_t(unsigned int, video->ep->maxburst, 1)
-		 * (video->ep->mult + 1);
+		 * (video->ep->mult);
 
 	for (i = 0; i < UVC_NUM_REQUESTS; ++i) {
 		video->req_buffer[i] = kmalloc(req_size, GFP_KERNEL);