Editing Special:Badtitle/NS100:EN/Using Moxa NPort 5450 Serial to IP Server with Linux Kernel Version 3.8.0 (tested with Ubuntu 13.04)

<summary>Unfortunately, [http://www.moxa.com/support/download.aspx?type=support&id=952 Moxa's NPort Real TTY Driver for Linux] is currently (version 1.18, released 2012/03/20) not compatible with Linux kernel 3.8.0. When I tried to install this driver for the NPort 5450 Serial to IP Server on my Ubuntu 13.04 machine (currently with kernel 3.8.0-27), the driver didn't compile. It turned out, that it is possible to patch the driver source code in order to get it work with Linux kernel 3.8.0 &ndash; here is a short documentation what I did.</summary>


=== Building the Patched Driver ===

<ol>
<li> Download the NPort Real TTY Driver for Linux in version 1.18.7 Build 13050317 [http://www.moxa.ru/forum/index.php?/topic/2383-%D0%BF%D1%80%D0%BE%D0%B1%D0%BB%D0%B5%D0%BC%D1%8B-%D1%81%D0%BE-%D1%81%D0%B1%D0%BE%D1%80%D0%BA%D0%BE%D0%B9-npreal-%D0%BD%D0%B0-opensuse-123-%D0%B8-alt-linux-60#entry8921 from this forum post (unofficial build, Russian forum)] </li>
<li> Prepare the code base for compilation:
<pre class="brush: plain;">
user@ubuntu:~$ tar -xzvf npreal2_1.18.7_Build_13050317.tgz -C /tmp
user@ubuntu:~$ cd /tmp/moxa
user@ubuntu:/tmp/moxa$ wget https://downloads.rene-schwarz.com/download/npreal2.c_1-18-7_b13050317.patch
user@ubuntu:/tmp/moxa$ patch < npreal2.c_1-18-7_b13050317.patch
</pre>
<ul>
<li>Extract the driver source code to <code>/tmp</code> (line 1).</li>
<li>Download the patch for <code>npreal2.c</code> [https://downloads.rene-schwarz.com/download/npreal2.c_1-18-7_b13050317.patch from here] (lines 2 et seq.).</li>
<li>Patch the C source file <code>npreal2.c</code> (line 4).</li>
</ul>
</li>
<li>You are now ready to compile and install the driver (root privileges required):
<pre class="brush: plain;">
user@ubuntu:/tmp/moxa$ sudo ./moxa/mxinst
</pre>
</li>
<li>The driver should compile now without any errors. If so, the driver should be properly installed now and you can configure it (please refer to <code>/tmp/moxa/README.TXT</code>).</li>
</ol>


=== Changes for Linux Kernel 3.8.0 ===

The changes that were necessary to let the driver compile against the Linux kernel 3.8.0 are the following (identical to the patch provided above):

<pre class="brush: diff;">
--- npreal2.c	Fri May 03 11:52:43 2013
+++ npreal2.c	Tue Aug 06 16:58:36 2013
@@ -426,6 +426,39 @@
 static struct semaphore 	npvar_tmp_buf_sem = MUTEX;
 #endif
 
+#if (LINUX_VERSION_CODE >= VERSION_CODE(3,8,0))
+struct n_tty_data {
+	unsigned int column;
+	unsigned long overrun_time;
+	int num_overrun;
+
+	unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
+	unsigned char echo_overrun:1;
+
+	DECLARE_BITMAP(process_char_map, 256);
+	DECLARE_BITMAP(read_flags, N_TTY_BUF_SIZE);
+
+	char *read_buf;
+	int read_head;
+	int read_tail;
+	int read_cnt;
+	int minimum_to_wake;
+
+	unsigned char *echo_buf;
+	unsigned int echo_pos;
+	unsigned int echo_cnt;
+
+	int canon_data;
+	unsigned long canon_head;
+	unsigned int canon_column;
+
+	struct mutex atomic_read_lock;
+	struct mutex output_lock;
+	struct mutex echo_lock;
+	raw_spinlock_t read_lock;
+};
+#endif
+
 #if (LINUX_VERSION_CODE < VERSION_CODE(2,4,0))
 static struct inode_operations npreal_net_iops;
 #endif
@@ -3436,7 +3469,21 @@
 }
 #endif
 
-#if ((LINUX_VERSION_CODE > VERSION_CODE(2,6,15)) || ((LINUX_VERSION_CODE == VERSION_CODE(2,6,15)) && defined(FEDORA)))
+#if (LINUX_VERSION_CODE >= VERSION_CODE(3,8,0))
+static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b)
+{
+    /* Dumb strategy for now - should keep some stats */
+    /* 	printk("Flip dispose %p\n", b); */
+    if (b->size >= 512)
+        kfree(b);
+    else
+    {
+        b->next = tty->port->buf.free;
+        tty->port->buf.free = b;
+    }
+}
+#endif
+#if ((LINUX_VERSION_CODE > VERSION_CODE(2,6,15) && LINUX_VERSION_CODE < VERSION_CODE(3,8,0)) || ((LINUX_VERSION_CODE == VERSION_CODE(2,6,15)) && defined(FEDORA)))
 static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b)
 {
     /* Dumb strategy for now - should keep some stats */
@@ -3514,11 +3561,20 @@
         tty->ldisc.receive_buf(tty, cp, fp, count);
         //DBGPRINT(MX_DEBUG_TRACE, "flush %d bytes\n", count);
 #else
-        spin_lock_irqsave(&tty->buf.lock, flags);
+#if (LINUX_VERSION_CODE >= VERSION_CODE(3,8,0))
+        spin_lock_irqsave(&tty->port->buf.lock, flags);
+	head = tty->port->buf.head;
+#else
+        spin_lock_irqsave(&tty->port->buf.lock, flags);
         head = tty->buf.head;
+#endif
         if (head != NULL)
         {
+#if (LINUX_VERSION_CODE >= VERSION_CODE(3,8,0))
+            tty->port->buf.head = NULL;
+#else
             tty->buf.head = NULL;
+#endif
             for (;;)
             {
                 count = head->commit - head->read;
@@ -3545,17 +3601,29 @@
                 cp = head->char_buf_ptr + head->read;
                 fp = head->flag_buf_ptr + head->read;
                 head->read += count;
+#if (LINUX_VERSION_CODE >= VERSION_CODE(3,8,0))
+                spin_unlock_irqrestore(&tty->port->buf.lock, flags);
+#else
                 spin_unlock_irqrestore(&tty->buf.lock, flags);
+#endif
 #if (LINUX_VERSION_CODE >= VERSION_CODE(2,6,27))
                 disc->ops->receive_buf(tty, cp, fp, count);
 #else
                 disc->receive_buf(tty, cp, fp, count);
 #endif
+#if (LINUX_VERSION_CODE >= VERSION_CODE(3,8,0))
+                spin_lock_irqsave(&tty->port->buf.lock, flags);
+            }
+            tty->port->buf.head = head;
+        }
+        spin_unlock_irqrestore(&tty->port->buf.lock, flags);
+#else
                 spin_lock_irqsave(&tty->buf.lock, flags);
             }
             tty->buf.head = head;
         }
         spin_unlock_irqrestore(&tty->buf.lock, flags);
+#endif
         tty_ldisc_deref(disc);
 #endif
     }
@@ -4303,6 +4371,7 @@
     int cnt;
     struct npreal_struct *info;
     struct tty_struct *	tty;
+    struct n_tty_data *ldata;
 
     /*
      *  Get the node pointer, and quit if it doesn't exist.
@@ -4350,6 +4419,10 @@
         up(&info->rx_semaphore);
         goto done;
     }
+#if (LINUX_VERSION_CODE >= VERSION_CODE(3,8,0))
+    ldata = tty->disc_data;
+#endif
+
 #if (LINUX_VERSION_CODE >= VERSION_CODE(2,1,0))
 #if 1
     if(!info->tty->low_latency)
@@ -4392,8 +4465,11 @@
         	* that erase characters will be handled.  Other excess
         	* characters will be beeped.
         	*/
-
-        if (!tty->icanon || tty->canon_data)
+#if (LINUX_VERSION_CODE >= VERSION_CODE(3,8,0))
+	if (!ldata->icanon || ldata->canon_data)
+#else
+	if (!tty->icanon || tty->canon_data)
+#endif
         {
 #if (LINUX_VERSION_CODE <  VERSION_CODE(2,1,0))
             if (!set_bit(TTY_THROTTLED,&tty->flags))
@@ -4408,9 +4484,15 @@
         up(&info->rx_semaphore);
         goto done;
     }
+#if (LINUX_VERSION_CODE >= VERSION_CODE(3,8,0))
+    if (!ldata->icanon || ldata->canon_data)
+    {
+        if ((cnt = MIN(cnt,(N_TTY_BUF_SIZE-1) - ldata->read_cnt )) <= 0)
+#else
     if (!tty->icanon || tty->canon_data)
     {
         if ((cnt = MIN(cnt,(N_TTY_BUF_SIZE-1) - tty->read_cnt )) <= 0)
+#endif
         {
 
             /*
</pre>


=== Driver Support for Other Moxa Products ===

This driver should also work for other Moxa products, namely the following ones:
* CN2510 Series
* CN2610/2650 Series
* MiiNePort E1 Series
* MiiNePort E2 Series
* MiiNePort E3 Series
* MiiNePort W1 Series
* NE-4000T/NE-4000T-ST
* NE-4100T
* NE-4110A
* NE-4110S
* NE-4120A
* NE-4120S
* NPort 5110/5130/5150 Series
* NPort 5110A/5130A/5150A Series
* NPort 5130
* NPort 5150
* NPort 5150AI-M12/5250AI-M12/5450AI-M12 Series
* NPort 5210/5230/5232 Series
* NPort 5210A/5230A/5250A Series
* NPort 5230 Series
* NPort 5410/5430/5450 Series
* NPort 5430 Series
* NPort 5450 Series
* NPort 5600-8-DT/5650-8-DT Series
* NPort 5610/5630 Series
* NPort 5610-8-DTL/5650-8-DTL Series
* NPort 5650 Series
* NPort 6150 Series
* NPort 6250 Series
* NPort 6450 Series
* NPort 6610/6650 Series
* NPort DE-311M
* NPort Express DE-211
* NPort Express DE-311
* NPort IA5150/5250 Series
* NPort IA5150A/IA5250A/IA5450A Series
* NPort P5150A Series
* NPort S8455/S8458 Series
* NPort Server Lite DE-301/302/304/331/332/334
* NPort Server Pro DE-303, DE-308
* NPort W2004 Series
* NPort W2150/2250 Plus
* NPort W2150A/W2250A
* NPort W2250/2150
* WE-2100T


=== References ===

* https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=ecbbfd44a08fa80e0d664814efd4c187721b85f6
* https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=ba2e68ac6157004ee4922fb39ebd9459bbae883e
* https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=53c5ee2cfb4dadc4f5c24fe671e2fbfc034c875e
* http://lxr.free-electrons.com/source/drivers/tty/n_tty.c

{{wl-publish: 2013-08-07 09:39:58 +0200 | René Schwarz }}