tty: n_hdlc add buffer flushing

Add flush_buffer tty callback to flush rx buffers.
Add TCFLSH ioctl processing to flush tx buffers.
Increase default tx buffers from 1 to 3.
Remove unneeded flush_buffer call in open callback.
Remove vendor specific CVS version string.

Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 37 insertions, 9 deletions

diff --git a/drivers/char/n_hdlc.c b/drivers/char/n_hdlc.c
index 461ece591a5b..1c43c8cdee25 100644
--- a/drivers/char/n_hdlc.c
+++ b/drivers/char/n_hdlc.c
@@ -10,7 +10,6 @@
  *      Paul Mackerras <Paul.Mackerras@cs.anu.edu.au>
  *
  * Original release 01/11/99
- * $Id: n_hdlc.c,v 4.8 2003/05/06 21:18:51 paulkf Exp $
  *
  * This code is released under the GNU General Public License (GPL)
  *
@@ -79,7 +78,6 @@
  */
 
 #define HDLC_MAGIC 0x239e
-#define HDLC_VERSION "$Revision: 4.8 $"
 
 #include <linux/module.h>
 #include <linux/init.h>
@@ -114,7 +112,7 @@
 #define MAX_HDLC_FRAME_SIZE 65535 
 #define DEFAULT_RX_BUF_COUNT 10
 #define MAX_RX_BUF_COUNT 60
-#define DEFAULT_TX_BUF_COUNT 1
+#define DEFAULT_TX_BUF_COUNT 3
 
 struct n_hdlc_buf {
         struct n_hdlc_buf *link;
@@ -199,6 +197,31 @@ static void n_hdlc_tty_wakeup(struct tty_struct *tty);
 #define tty2n_hdlc(tty) ((struct n_hdlc *) ((tty)->disc_data))
 #define n_hdlc2tty(n_hdlc)      ((n_hdlc)->tty)
 
+static void flush_rx_queue(struct tty_struct *tty)
+{
+        struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
+        struct n_hdlc_buf *buf;
+
+        while ((buf = n_hdlc_buf_get(&n_hdlc->rx_buf_list)))
+                n_hdlc_buf_put(&n_hdlc->rx_free_buf_list, buf);
+}
+
+static void flush_tx_queue(struct tty_struct *tty)
+{
+        struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
+        struct n_hdlc_buf *buf;
+        unsigned long flags;
+
+        while ((buf = n_hdlc_buf_get(&n_hdlc->tx_buf_list)))
+                n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, buf);
+        spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
+        if (n_hdlc->tbuf) {
+                n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, n_hdlc->tbuf);
+                n_hdlc->tbuf = NULL;
+        }
+        spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
+}
+
 static struct tty_ldisc_ops n_hdlc_ldisc = {
         .owner          = THIS_MODULE,
         .magic          = TTY_LDISC_MAGIC,
@@ -211,6 +234,7 @@ static struct tty_ldisc_ops n_hdlc_ldisc = {
         .poll           = n_hdlc_tty_poll,
         .receive_buf    = n_hdlc_tty_receive,
         .write_wakeup   = n_hdlc_tty_wakeup,
+        .flush_buffer   = flush_rx_queue,
 };
 
 /**
@@ -341,10 +365,7 @@ static int n_hdlc_tty_open (struct tty_struct *tty)
         set_bit(TTY_NO_WRITE_SPLIT,&tty->flags);
 #endif
         
-        /* Flush any pending characters in the driver and discipline. */
-        if (tty->ldisc->ops->flush_buffer)
-                tty->ldisc->ops->flush_buffer(tty);
-
+        /* flush receive data from driver */
         tty_driver_flush_buffer(tty);
                 
         if (debuglevel >= DEBUG_LEVEL_INFO)     
@@ -763,6 +784,14 @@ static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file,
                 error = put_user(count, (int __user *)arg);
                 break;
 
+        case TCFLSH:
+                switch (arg) {
+                case TCIOFLUSH:
+                case TCOFLUSH:
+                        flush_tx_queue(tty);
+                }
+                /* fall through to default */
+
         default:
                 error = n_tty_ioctl_helper(tty, file, cmd, arg);
                 break;
@@ -919,8 +948,7 @@ static struct n_hdlc_buf* n_hdlc_buf_get(struct n_hdlc_buf_list *list)
 }       /* end of n_hdlc_buf_get() */
 
 static char hdlc_banner[] __initdata =
-        KERN_INFO "HDLC line discipline: version " HDLC_VERSION
-        ", maxframe=%u\n";
+        KERN_INFO "HDLC line discipline maxframe=%u\n";
 static char hdlc_register_ok[] __initdata =
         KERN_INFO "N_HDLC line discipline registered.\n";
 static char hdlc_register_fail[] __initdata =