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

BugLink: http://bugs.launchpad.net/bugs/1655969
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 8cf00f6ed0433cfe1fa40862f339fdf0a012721b..e2641d4dfdd6a928d6ee70559311aaf4fefe04f1 100644 (file)
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -148,7 +148,12 @@ 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;
 
@@ -165,7 +170,7 @@ 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/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index 3d0d5d94a62f2fe6927983ba6979784eb20eceeb..0f01c04d7cbd856581da53d6e69cba5f50b2c922 100644 (file)
--- 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);