From: Mike Lockwood <lockwood@android.com>
Date: Mon, 7 Feb 2011 16:51:07 +0000 (-0500)
Subject: USB: gadget: f_mtp: Fix problems transferring files from device to host
X-Git-Tag: 2.1b_release~2647
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1b44e9c94df84e01cafd6e8f86df90a3a60502dd;p=platform%2Fkernel%2Fkernel-mfld-blackbay.git

USB: gadget: f_mtp: Fix problems transferring files from device to host

Exit from send_file_work immediately when a cancel request is received.

Only busy status if there is a cancel pending that has not been repoorted to userspace.
This avoids a race condition that can occur when mtp_read resets the state
to STATE_BUSY before we report status OK back to the host.

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 e07224f..d560fbc 100644
--- a/drivers/usb/gadget/f_mtp.c
+++ b/drivers/usb/gadget/f_mtp.c
@@ -662,6 +662,10 @@ static void send_file_work(struct work_struct *data) {
 		ret = wait_event_interruptible(dev->write_wq,
 			(req = req_get(dev, &dev->tx_idle))
 			|| dev->state != STATE_BUSY);
+		if (dev->state == STATE_CANCELED) {
+			r = -ECANCELED;
+			break;
+		}
 		if (!req) {
 			r = ret;
 			break;
@@ -1098,14 +1102,13 @@ static int mtp_function_setup(struct usb_function *f,
 			/* device status is "busy" until we report
 			 * the cancelation to userspace
 			 */
-			if (dev->state == STATE_BUSY
-					|| dev->state == STATE_CANCELED)
+			if (dev->state == STATE_CANCELED)
 				status->wCode =
 					__cpu_to_le16(MTP_RESPONSE_DEVICE_BUSY);
 			else
 				status->wCode =
 					__cpu_to_le16(MTP_RESPONSE_OK);
-				spin_unlock_irqrestore(&dev->lock, flags);
+			spin_unlock_irqrestore(&dev->lock, flags);
 			value = sizeof(*status);
 		}
 	}
@@ -1185,7 +1188,7 @@ static void mtp_function_disable(struct usb_function *f)
 static int mtp_bind_config(struct usb_configuration *c)
 {
 	struct mtp_dev *dev;
-	int ret;
+	int ret = 0;
 
 	printk(KERN_INFO "mtp_bind_config\n");