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usb: gadget: loopback: don't queue requests to bogus endpoints

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A request allocated from e.g. ep1out cannot
be queued to any other endpoint. This bug has
been in f_loopback at least since mid-2011 and
since nobody has really screamed about it, we're
not backporting to any stable kernels.

Debugged with MUSB since that's the only controller
which complains about this case.

Signed-off-by: Felipe Balbi <balbi@ti.com>
This commit is contained in:
Felipe Balbi 2014-10-13 15:30:52 -05:00
parent c0d31b3c3d
commit e0857ce58e
1 changed files with 43 additions and 46 deletions
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89
drivers/usb/gadget/function/f_loopback.c
View file

@ -253,22 +253,13 @@ static void loopback_complete(struct usb_ep *ep, struct usb_request *req)
case 0: /* normal completion? */
if (ep == loop->out_ep) {
/* loop this OUT packet back IN to the host */
req->zero = (req->actual < req->length);
req->length = req->actual;
status = usb_ep_queue(loop->in_ep, req, GFP_ATOMIC);
if (status == 0)
return;
/* "should never get here" */
ERROR(cdev, "can't loop %s to %s: %d\n",
ep->name, loop->in_ep->name,
status);
}
/* queue the buffer for some later OUT packet */
req->length = buflen;
status = usb_ep_queue(loop->out_ep, req, GFP_ATOMIC);
status = usb_ep_queue(ep, req, GFP_ATOMIC);
if (status == 0)
return;
@ -308,60 +299,66 @@ static inline struct usb_request *lb_alloc_ep_req(struct usb_ep *ep, int len)
return alloc_ep_req(ep, len, buflen);
}
static int
enable_loopback(struct usb_composite_dev *cdev, struct f_loopback *loop)
static int enable_endpoint(struct usb_composite_dev *cdev, struct f_loopback *loop,
struct usb_ep *ep)
{
int result = 0;
struct usb_ep *ep;
struct usb_request *req;
unsigned i;
int result;
/* one endpoint writes data back IN to the host */
ep = loop->in_ep;
result = config_ep_by_speed(cdev->gadget, &(loop->function), ep);
if (result)
return result;
result = usb_ep_enable(ep);
if (result < 0)
return result;
ep->driver_data = loop;
/* one endpoint just reads OUT packets */
ep = loop->out_ep;
/*
* one endpoint writes data back IN to the host while another endpoint
* just reads OUT packets
*/
result = config_ep_by_speed(cdev->gadget, &(loop->function), ep);
if (result)
goto fail0;
result = usb_ep_enable(ep);
if (result < 0) {
fail0:
ep = loop->in_ep;
usb_ep_disable(ep);
ep->driver_data = NULL;
return result;
}
if (result < 0)
goto fail0;
ep->driver_data = loop;
/* allocate a bunch of read buffers and queue them all at once.
/*
* allocate a bunch of read buffers and queue them all at once.
* we buffer at most 'qlen' transfers; fewer if any need more
* than 'buflen' bytes each.
*/
for (i = 0; i < qlen && result == 0; i++) {
req = lb_alloc_ep_req(ep, 0);
if (req) {
req->complete = loopback_complete;
result = usb_ep_queue(ep, req, GFP_ATOMIC);
if (result)
ERROR(cdev, "%s queue req --> %d\n",
ep->name, result);
} else {
usb_ep_disable(ep);
ep->driver_data = NULL;
result = -ENOMEM;
goto fail0;
if (!req)
goto fail1;
req->complete = loopback_complete;
result = usb_ep_queue(ep, req, GFP_ATOMIC);
if (result) {
ERROR(cdev, "%s queue req --> %d\n",
ep->name, result);
goto fail1;
}
}
return 0;
fail1:
usb_ep_disable(ep);
fail0:
return result;
}
static int
enable_loopback(struct usb_composite_dev *cdev, struct f_loopback *loop)
{
int result = 0;
result = enable_endpoint(cdev, loop, loop->in_ep);
if (result)
return result;
result = enable_endpoint(cdev, loop, loop->out_ep);
if (result)
return result;
DBG(cdev, "%s enabled\n", loop->function.name);
return result;
}