[PATCH] 2.5.8 n_hdlc.c

Remove localy defined wait queues and use wait queues
in tty structure of same function. This matches the
n_tty.c behavior.

Handle pty hangup when blocked on read.

These 2 changes fix use of n_hdlc with PPPoATM and
are mirror changes included in 2.4.19-pre

diff --git a/drivers/char/n_hdlc.c b/drivers/char/n_hdlc.c
index 6058bf8782c205484687055ab2bd48e75fb46d95..b0dcc32b53ce3afda03c12b5acd8b7d943ca9535 100644 (file)
--- a/drivers/char/n_hdlc.c
+++ b/drivers/char/n_hdlc.c
@@ -9,7 +9,7 @@
  *     Al Longyear <longyear@netcom.com>, Paul Mackerras <Paul.Mackerras@cs.anu.edu.au>
  *
  * Original release 01/11/99
- * $Id: n_hdlc.c,v 3.2 2000/11/06 22:34:38 paul Exp $
+ * $Id: n_hdlc.c,v 4.1 2002/04/10 19:30:58 paulkf Exp $
  *
  * This code is released under the GNU General Public License (GPL)
  *
@@ -78,7 +78,7 @@
  */
 
 #define HDLC_MAGIC 0x239e
-#define HDLC_VERSION "3.2"
+#define HDLC_VERSION "$Revision: 4.1 $"
 
 #include <linux/version.h>
 #include <linux/config.h>
@@ -159,11 +159,6 @@ struct n_hdlc {
        struct tty_struct *tty;         /* ptr to TTY structure */
        struct tty_struct *backup_tty;  /* TTY to use if tty gets closed */
        
-       /* Queues for select() functionality */
-       wait_queue_head_t read_wait;
-       wait_queue_head_t write_wait;
-       wait_queue_head_t poll_wait;
-
        int             tbusy;          /* reentrancy flag for tx wakeup code */
        int             woke_up;
        N_HDLC_BUF      *tbuf;          /* currently transmitting tx buffer */
@@ -234,9 +229,8 @@ static void n_hdlc_release (struct n_hdlc *n_hdlc)
                printk("%s(%d)n_hdlc_release() called\n",__FILE__,__LINE__);
                
        /* Ensure that the n_hdlcd process is not hanging on select()/poll() */
-       wake_up_interruptible (&n_hdlc->read_wait);
-       wake_up_interruptible (&n_hdlc->poll_wait);
-       wake_up_interruptible (&n_hdlc->write_wait);
+       wake_up_interruptible (&tty->read_wait);
+       wake_up_interruptible (&tty->write_wait);
 
        if (tty != NULL && tty->disc_data == n_hdlc)
                tty->disc_data = NULL;  /* Break the tty->n_hdlc link */
@@ -431,8 +425,7 @@ static void n_hdlc_send_frames (struct n_hdlc *n_hdlc, struct tty_struct *tty)
                        n_hdlc->tbuf = NULL;
                        
                        /* wait up sleeping writers */
-                       wake_up_interruptible(&n_hdlc->write_wait);
-                       wake_up_interruptible(&n_hdlc->poll_wait);
+                       wake_up_interruptible(&tty->write_wait);
        
                        /* get next pending transmit buffer */
                        tbuf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);
@@ -574,8 +567,7 @@ static void n_hdlc_tty_receive(struct tty_struct *tty,
        n_hdlc_buf_put(&n_hdlc->rx_buf_list,buf);
        
        /* wake up any blocked reads and perform async signalling */
-       wake_up_interruptible (&n_hdlc->read_wait);
-       wake_up_interruptible (&n_hdlc->poll_wait);
+       wake_up_interruptible (&tty->read_wait);
        if (n_hdlc->tty->fasync != NULL)
                kill_fasync (&n_hdlc->tty->fasync, SIGIO, POLL_IN);
 
@@ -620,6 +612,9 @@ static rw_ret_t n_hdlc_tty_read (struct tty_struct *tty,
        }
 
        for (;;) {
+               if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+                       return -EIO;
+
                n_hdlc = tty2n_hdlc (tty);
                if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC ||
                         tty != n_hdlc->tty)
@@ -633,7 +628,7 @@ static rw_ret_t n_hdlc_tty_read (struct tty_struct *tty,
                if (file->f_flags & O_NONBLOCK)
                        return -EAGAIN;
                        
-               interruptible_sleep_on (&n_hdlc->read_wait);
+               interruptible_sleep_on (&tty->read_wait);
                if (signal_pending(current))
                        return -EINTR;
        }
@@ -702,7 +697,7 @@ static rw_ret_t n_hdlc_tty_write (struct tty_struct *tty, struct file *file,
                count = maxframe;
        }
        
-       add_wait_queue(&n_hdlc->write_wait, &wait);
+       add_wait_queue(&tty->write_wait, &wait);
        set_current_state(TASK_INTERRUPTIBLE);
        
        /* Allocate transmit buffer */
@@ -725,7 +720,7 @@ static rw_ret_t n_hdlc_tty_write (struct tty_struct *tty, struct file *file,
        }
 
        set_current_state(TASK_RUNNING);
-       remove_wait_queue(&n_hdlc->write_wait, &wait);
+       remove_wait_queue(&tty->write_wait, &wait);
 
        if (!error) {           
                /* Retrieve the user's buffer */
@@ -835,12 +830,14 @@ static unsigned int n_hdlc_tty_poll (struct tty_struct *tty,
        if (n_hdlc && n_hdlc->magic == HDLC_MAGIC && tty == n_hdlc->tty) {
                /* queue current process into any wait queue that */
                /* may awaken in the future (read and write) */
-               poll_wait(filp, &n_hdlc->poll_wait, wait);
+
+               poll_wait(filp, &tty->read_wait, wait);
+               poll_wait(filp, &tty->write_wait, wait);
 
                /* set bits for operations that wont block */
                if(n_hdlc->rx_buf_list.head)
                        mask |= POLLIN | POLLRDNORM;    /* readable */
-               if(tty->flags & (1 << TTY_OTHER_CLOSED))
+               if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
                        mask |= POLLHUP;
                if(tty_hung_up_p(filp))
                        mask |= POLLHUP;
@@ -894,11 +891,7 @@ static struct n_hdlc *n_hdlc_alloc (void)
        
        /* Initialize the control block */
        n_hdlc->magic  = HDLC_MAGIC;
-
        n_hdlc->flags  = 0;
-       init_waitqueue_head(&n_hdlc->read_wait);
-       init_waitqueue_head(&n_hdlc->poll_wait);
-       init_waitqueue_head(&n_hdlc->write_wait);
        
        return n_hdlc;