From 3bf08eceb117d921214a72673d691a4485150282 Mon Sep 17 00:00:00 2001
From: Yi-Shin Li <ysli@xxxxxxxxxxxxx>
Date: Sun, 11 Jul 2010 23:08:11 +0800
Subject: [PATCH] bug fix for async write and read

* In ftdi_write_data_cb(), the tc->offset should be accumulated with
  transfer->actual_length.

* In ftdi_transfer_data_done(), the tc->transfer could be NULL if
  "(size <= ftdi->readbuffer_remaining)" at ftdi_read_data_submit().
  Therefore, has to check if it's NULL before accessing it.

* add autogen.sh

* add "./m4" to .gitignore
---
 .gitignore |    1 +
 autogen.sh |   48 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/ftdi.c |   31 ++++++++++++++++++-------------
 3 files changed, 67 insertions(+), 13 deletions(-)
 create mode 100755 autogen.sh

diff --git a/.gitignore b/.gitignore
index 4bacdb7..e1a8385 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,6 +10,7 @@
 build/
 
 # Automake
+m4/
 Makefile
 Makefile.in
 autom4te.cache
diff --git a/autogen.sh b/autogen.sh
new file mode 100755
index 0000000..cd18fbd
--- /dev/null
+++ b/autogen.sh
@@ -0,0 +1,48 @@
+#! /bin/sh
+
+# $Id: autogen.sh,v 1.4 2002/12/02 01:39:49 murrayc Exp $
+#
+# Copyright (c) 2002  Daniel Elstner  <daniel.elstner@xxxxxxx>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License VERSION 2 as
+# published by the Free Software Foundation.  You are not allowed to
+# use any other version of the license; unless you got the explicit
+# permission from the author to do so.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+
+dir=`echo "$0" | sed 's,[^/]*$,,'`
+test "x${dir}" = "x" && dir='.'
+
+if test "x`cd "${dir}" 2>/dev/null && pwd`" != "x`pwd`"
+then
+    echo "This script must be executed directly from the source directory."
+    exit 1
+fi
+
+rm -f config.cache acconfig.h
+
+echo "- libtoolize."		&& \
+libtoolize --force --copy	&& \
+echo "- aclocal."		&& \
+aclocal				&& \
+echo "- autoconf."		&& \
+autoconf			&& \
+echo "- autoheader."		&& \
+autoheader			&& \
+echo "- automake."		&& \
+automake --add-missing --copy --gnu	&& \
+echo				&& \
+./configure "$@"		&& exit 0
+
+exit 1
+
diff --git a/src/ftdi.c b/src/ftdi.c
index b22a55b..4a57957 100644
--- a/src/ftdi.c
+++ b/src/ftdi.c
@@ -1322,9 +1322,9 @@ static void ftdi_write_data_cb(struct libusb_transfer *transfer)
 {
     struct ftdi_transfer_control *tc = (struct ftdi_transfer_control *) transfer->user_data;
     struct ftdi_context *ftdi = tc->ftdi;
-
-    tc->offset = transfer->actual_length;
-
+    
+    tc->offset += transfer->actual_length;
+    
     if (tc->offset == tc->size)
     {
         tc->completed = 1;
@@ -1387,10 +1387,12 @@ struct ftdi_transfer_control *ftdi_write_data_submit(struct ftdi_context *ftdi,
       write_size = size;
     else
       write_size = ftdi->writebuffer_chunksize;
-
-    libusb_fill_bulk_transfer(transfer, ftdi->usb_dev, ftdi->in_ep, buf, write_size, ftdi_write_data_cb, tc, ftdi->usb_write_timeout);
+    
+    libusb_fill_bulk_transfer(transfer, ftdi->usb_dev, ftdi->in_ep, buf,
+                              write_size, ftdi_write_data_cb, tc,
+                              ftdi->usb_write_timeout);
     transfer->type = LIBUSB_TRANSFER_TYPE_BULK;
-
+        
     ret = libusb_submit_transfer(transfer);
     if (ret < 0)
     {
@@ -1514,17 +1516,20 @@ int ftdi_transfer_data_done(struct ftdi_transfer_control *tc)
                     break;
             libusb_free_transfer(tc->transfer);
             free (tc);
-            tc = NULL;
             return ret;
         }
     }
 
-    if (tc->transfer->status == LIBUSB_TRANSFER_COMPLETED)
-        ret = tc->offset;
-    else
-        ret = -1;
-
-    libusb_free_transfer(tc->transfer);
+    ret = tc->offset;
+    /**
+     * tc->transfer could be NULL if "(size <= ftdi->readbuffer_remaining)"
+     * at ftdi_read_data_submit(). Therefore, has to check it here.
+     **/
+    if (tc->transfer) {
+      if (tc->transfer->status != LIBUSB_TRANSFER_COMPLETED)
+          ret = -1;
+      libusb_free_transfer(tc->transfer);
+    }
     free(tc);
     return ret;
 }
-- 
1.7.0.4