Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / drivers / tty / n_hdlc.c

diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index 47d32281032c75322b1181c65ab710f00b7967c6..52fc0c9a6364e05edc80e8bdf4e4d28250f9a754 100644 (file)
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -581,8 +581,9 @@ static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
                           __u8 __user *buf, size_t nr)
 {
        struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
-       int ret;
+       int ret = 0;
        struct n_hdlc_buf *rbuf;
+       DECLARE_WAITQUEUE(wait, current);
 
        if (debuglevel >= DEBUG_LEVEL_INFO)     
                printk("%s(%d)n_hdlc_tty_read() called\n",__FILE__,__LINE__);
@@ -598,57 +599,55 @@ static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
                return -EFAULT;
        }
 
-       tty_lock();
+       add_wait_queue(&tty->read_wait, &wait);
 
        for (;;) {
                if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
-                       tty_unlock();
-                       return -EIO;
+                       ret = -EIO;
+                       break;
                }
+               if (tty_hung_up_p(file))
+                       break;
 
-               n_hdlc = tty2n_hdlc (tty);
-               if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC ||
-                        tty != n_hdlc->tty) {
-                       tty_unlock();
-                       return 0;
-               }
+               set_current_state(TASK_INTERRUPTIBLE);
 
                rbuf = n_hdlc_buf_get(&n_hdlc->rx_buf_list);
-               if (rbuf)
+               if (rbuf) {
+                       if (rbuf->count > nr) {
+                               /* too large for caller's buffer */
+                               ret = -EOVERFLOW;
+                       } else {
+                               if (copy_to_user(buf, rbuf->buf, rbuf->count))
+                                       ret = -EFAULT;
+                               else
+                                       ret = rbuf->count;
+                       }
+
+                       if (n_hdlc->rx_free_buf_list.count >
+                           DEFAULT_RX_BUF_COUNT)
+                               kfree(rbuf);
+                       else
+                               n_hdlc_buf_put(&n_hdlc->rx_free_buf_list, rbuf);
                        break;
+               }
                        
                /* no data */
                if (file->f_flags & O_NONBLOCK) {
-                       tty_unlock();
-                       return -EAGAIN;
+                       ret = -EAGAIN;
+                       break;
                }
-                       
-               interruptible_sleep_on (&tty->read_wait);
+
+               schedule();
+
                if (signal_pending(current)) {
-                       tty_unlock();
-                       return -EINTR;
+                       ret = -EINTR;
+                       break;
                }
        }
-               
-       if (rbuf->count > nr)
-               /* frame too large for caller's buffer (discard frame) */
-               ret = -EOVERFLOW;
-       else {
-               /* Copy the data to the caller's buffer */
-               if (copy_to_user(buf, rbuf->buf, rbuf->count))
-                       ret = -EFAULT;
-               else
-                       ret = rbuf->count;
-       }
-       
-       /* return HDLC buffer to free list unless the free list */
-       /* count has exceeded the default value, in which case the */
-       /* buffer is freed back to the OS to conserve memory */
-       if (n_hdlc->rx_free_buf_list.count > DEFAULT_RX_BUF_COUNT)
-               kfree(rbuf);
-       else    
-               n_hdlc_buf_put(&n_hdlc->rx_free_buf_list,rbuf);
-       tty_unlock();
+
+       remove_wait_queue(&tty->read_wait, &wait);
+       __set_current_state(TASK_RUNNING);
+
        return ret;
        
 }      /* end of n_hdlc_tty_read() */
@@ -691,14 +690,15 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
                count = maxframe;
        }
        
-       tty_lock();
-
        add_wait_queue(&tty->write_wait, &wait);
-       set_current_state(TASK_INTERRUPTIBLE);
+
+       for (;;) {
+               set_current_state(TASK_INTERRUPTIBLE);
        
-       /* Allocate transmit buffer */
-       /* sleep until transmit buffer available */             
-       while (!(tbuf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list))) {
+               tbuf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list);
+               if (tbuf)
+                       break;
+
                if (file->f_flags & O_NONBLOCK) {
                        error = -EAGAIN;
                        break;
@@ -719,7 +719,7 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
                }
        }
 
-       set_current_state(TASK_RUNNING);
+       __set_current_state(TASK_RUNNING);
        remove_wait_queue(&tty->write_wait, &wait);
 
        if (!error) {           
@@ -731,7 +731,7 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
                n_hdlc_buf_put(&n_hdlc->tx_buf_list,tbuf);
                n_hdlc_send_frames(n_hdlc,tty);
        }
-       tty_unlock();
+
        return error;
        
 }      /* end of n_hdlc_tty_write() */