Release MMQ device only once (not 4 times)
diff --git a/usbutils.c b/usbutils.c
index 6b2997e..a4527a8 100644
--- a/usbutils.c
+++ b/usbutils.c
@@ -859,6 +859,10 @@ static void release_cgpu(struct cgpu_info *cgpu)
struct cgpu_info *lookcgpu;
int i;
+ // It has already been done
+ if (cgpu->usbinfo.nodev)
+ return;
+
cgpu->usbinfo.nodev = true;
cgpu->usbinfo.nodev_count++;
gettimeofday(&(cgpu->usbinfo.last_nodev), NULL);