[PATCH 3.16.y-ckt 056/180] usb: gadget: printer: enqueue printer's response for setup request

[Luis Henriques]

3.16.7-ckt11 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andrzej Pietrasiewicz <andrzej.p at samsung.com>

commit eb132ccbdec5df46e29c9814adf76075ce83576b upstream.

Function-specific setup requests should be handled in such a way, that
apart from filling in the data buffer, the requests are also actually
enqueued: if function-specific setup is called from composte_setup(),
the "usb_ep_queue()" block of code in composite_setup() is skipped.

The printer function lacks this part and it results in e.g. get device id
requests failing: the host expects some response, the device prepares it
but does not equeue it for sending to the host, so the host finally asserts
timeout.

This patch adds enqueueing the prepared responses.

Fixes: 2e87edf49227: "usb: gadget: make g_printer use composite"
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p at samsung.com>
Signed-off-by: Felipe Balbi <balbi at ti.com>
[ luis: backported to 3.16:
  - file rename: drivers/usb/gadget/legacy/printer.c ->
    drivers/usb/gadget/printer.c ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/usb/gadget/printer.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/usb/gadget/printer.c b/drivers/usb/gadget/printer.c
index 6474081dcbaf..c9c6dae75c13 100644
--- a/drivers/usb/gadget/printer.c
+++ b/drivers/usb/gadget/printer.c
@@ -980,6 +980,15 @@ unknown:
 		break;
 	}
 	/* host either stalls (value < 0) or reports success */
+	if (value >= 0) {
+		req->length = value;
+		req->zero = value < wLength;
+		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
+		if (value < 0) {
+			ERROR(dev, "%s:%d Error!\n", __func__, __LINE__);
+			req->status = 0;
+		}
+	}
 	return value;
 }