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path: root/drivers/tty/n_hdlc.c
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Diffstat (limited to 'drivers/tty/n_hdlc.c')
-rw-r--r--drivers/tty/n_hdlc.c90
1 files changed, 45 insertions, 45 deletions
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index 47d32281032..52fc0c9a636 100644
--- 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() */