From 8d1604a2e3c70f4aacaef32bc265ce9b7aff36c1 Mon Sep 17 00:00:00 2001
From: Con Kolivas <kernel@kolivas.org>
Date: Mon, 14 Oct 2013 09:40:23 +1100
Subject: [PATCH] Do not use locking on usb callback function pthread
 signalling to prevent deadlock with libusb's own event lock.

---
 usbutils.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/usbutils.c b/usbutils.c
index 03fac7d1..549db214 100644
--- a/usbutils.c
+++ b/usbutils.c
@@ -2248,9 +2248,7 @@ static void LIBUSB_CALL transfer_callback(struct libusb_transfer *transfer)
 {
 	struct usb_transfer *ut = transfer->user_data;
 
-	mutex_lock(&ut->mutex);
 	pthread_cond_signal(&ut->cond);
-	mutex_unlock(&ut->mutex);
 }
 
 /* Wait for callback function to tell us it has finished the USB transfer, but
@@ -2272,7 +2270,6 @@ static int callback_wait(struct usb_transfer *ut, int *transferred, unsigned int
 		libusb_cancel_transfer(transfer);
 
 		/* Now wait for the callback function to be invoked. */
-		mutex_lock(&ut->mutex);
 		pthread_cond_wait(&ut->cond, &ut->mutex);
 	}
 	ret = transfer->status;