From: Mike Lockwood <lockwood@android.com>
Date: Sat, 19 Feb 2011 20:33:17 +0000 (-0500)
Subject: USB: gadget: f_mtp: dequeue request on error in mtp_read
X-Git-Tag: firefly_0821_release~7613^2~654
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=43f3dc8f5cab19d2baeb3d8d4d6fc01e2d19c337;p=firefly-linux-kernel-4.4.55.git

USB: gadget: f_mtp: dequeue request on error in mtp_read

In mtp_read(), if wait_event_interruptible() returns an error, we need to
remove the request from the EP queue.  Else, on the next call to mtp_read(), we
will attempt to enqueue the request again, potentially corrupting the
queue.  This is what happens with musb_gadget_queue(), which does not check for
duplicate requests.

Based on a similar change to f_adb.c

Signed-off-by: Mike Lockwood <lockwood@android.com>
---

diff --git a/drivers/usb/gadget/f_mtp.c b/drivers/usb/gadget/f_mtp.c
index 8128b203e76f..92dd89b340bc 100644
--- a/drivers/usb/gadget/f_mtp.c
+++ b/drivers/usb/gadget/f_mtp.c
@@ -504,6 +504,7 @@ requeue_req:
 	ret = wait_event_interruptible(dev->read_wq, dev->rx_done);
 	if (ret < 0) {
 		r = ret;
+		usb_ep_dequeue(dev->ep_out, req);
 		goto done;
 	}
 	if (dev->state == STATE_BUSY) {