diff options
| -rw-r--r-- | drivers/tty/n_hdlc.c | 90 |
1 files changed, 45 insertions, 45 deletions
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c index 47d32281032c..52fc0c9a6364 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() */ |