patch "usb: gadget: composite: correctly initialize ep->maxpacket" added to usb-testing

patch "usb: gadget: composite: correctly initialize ep->maxpacket" added to usb-testing

[gregkh]

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

    usb: gadget: composite: correctly initialize ep->maxpacket

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-testing 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 be merged to the usb-next branch sometime soon,
after it passes testing, and the merge window is open.

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


>From e8f29bb719b47a234f33b0af62974d7a9521a52c Mon Sep 17 00:00:00 2001
From: Felipe Balbi <felipe.balbi@linux.intel.com>
Date: Wed, 28 Sep 2016 10:38:11 +0300
Subject: usb: gadget: composite: correctly initialize ep->maxpacket

usb_endpoint_maxp() returns wMaxPacketSize in its
raw form. Without taking into consideration that it
also contains other bits reserved for isochronous
endpoints.

This patch fixes one occasion where this is a
problem by making sure that we initialize
ep->maxpacket only with lower 10 bits of the value
returned by usb_endpoint_maxp(). Note that seperate
patches will be necessary to audit all call sites of
usb_endpoint_maxp() and make sure that
usb_endpoint_maxp() only returns lower 10 bits of
wMaxPacketSize.

Cc: <stable@vger.kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
---
 drivers/usb/gadget/composite.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 32176f779861..f6a7583ab6d1 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -197,7 +197,7 @@ int config_ep_by_speed(struct usb_gadget *g,
 
 ep_found:
 	/* commit results */
-	_ep->maxpacket = usb_endpoint_maxp(chosen_desc);
+	_ep->maxpacket = usb_endpoint_maxp(chosen_desc) & 0x7ff;
 	_ep->desc = chosen_desc;
 	_ep->comp_desc = NULL;
 	_ep->maxburst = 0;
-- 
2.10.2