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>

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index f6a7583..0426d3c 100644 (file)
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -201,7 +201,12 @@ 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_mult(_ep->desc);
+
        if (!want_comp_desc)
                return 0;
 
@@ -218,7 +223,7 @@ 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 3d0d5d9..0f01c04 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);