From: Thomas Jarosch <thomas.jarosch@intra2net.com>
Date: Fri, 7 Oct 2011 13:59:54 +0000 (+0200)
Subject: Interface can not be changed on an already open device
X-Git-Tag: v1.0rc1~58
X-Git-Url: http://developer.intra2net.com/git/?p=libftdi;a=commitdiff_plain;h=1c5fa36b67bc30742eee94ed3e3648fcd4640f24;hp=cd2ead2f23cea38de6fdbf2459c79cb4936fbf8d

Interface can not be changed on an already open device

Based upon code from Uwe Bonnes, improved by me.
---

diff --git a/src/ftdi.c b/src/ftdi.c
index 1f45e95..59a9eea 100644
--- a/src/ftdi.c
+++ b/src/ftdi.c
@@ -149,12 +149,23 @@ struct ftdi_context *ftdi_new(void)
     \retval  0: all fine
     \retval -1: unknown interface
     \retval -2: USB device unavailable
+    \retval -3: Device already open, interface can't be set in that state
 */
 int ftdi_set_interface(struct ftdi_context *ftdi, enum ftdi_interface interface)
 {
     if (ftdi == NULL)
         ftdi_error_return(-2, "USB device unavailable");
 
+    if (ftdi->usb_dev != NULL)
+    {
+        int check_interface = interface;
+        if (check_interface == INTERFACE_ANY)
+            check_interface = INTERFACE_A;
+
+        if (ftdi->index != check_interface)
+            ftdi_error_return(-3, "Interface can not be changed on an already open device");
+    }
+
     switch (interface)
     {
         case INTERFACE_ANY: