patch "usb: gadget: composite: always set ep->mult to a sensible value" added to usb-next

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

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

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-next branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will also be merged in the next major kernel release
during the merge window.

If you have any questions about this process, please let me know.


>From eaa496ffaaf19591fe471a36cef366146eeb9153 Mon Sep 17 00:00:00 2001
From: Felipe Balbi <felipe.balbi@linux.intel.com>
Date: Wed, 28 Sep 2016 12:33:31 +0300
Subject: usb: gadget: composite: always set ep->mult to a sensible value

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.

Cc: <stable@vger.kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
---
 drivers/usb/gadget/composite.c          | 9 +++++++--
 drivers/usb/gadget/function/uvc_video.c | 2 +-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index f6a7583ab6d1..0426d3c1fff9 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -201,7 +201,12 @@ int config_ep_by_speed(struct usb_gadget *g,
 	_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_mult(_ep->desc);
+
 	if (!want_comp_desc)
 		return 0;
 
@@ -218,7 +223,7 @@ int config_ep_by_speed(struct usb_gadget *g,
 		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/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index 3d0d5d94a62f..0f01c04d7cbd 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -243,7 +243,7 @@ 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);
-- 
2.10.2