diff options
Diffstat (limited to 'drivers/tty/n_tty.c')
-rw-r--r-- | drivers/tty/n_tty.c | 90 |
1 files changed, 42 insertions, 48 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 2e900a9..9e3b216 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -321,7 +321,8 @@ static void n_tty_check_unthrottle(struct tty_struct *tty) static inline void put_tty_queue(unsigned char c, struct n_tty_data *ldata) { - *read_buf_addr(ldata, ldata->read_head++) = c; + *read_buf_addr(ldata, ldata->read_head) = c; + ldata->read_head++; } /** @@ -351,13 +352,13 @@ static void n_tty_packet_mode_flush(struct tty_struct *tty) { unsigned long flags; - spin_lock_irqsave(&tty->ctrl_lock, flags); if (tty->link->packet) { + spin_lock_irqsave(&tty->ctrl_lock, flags); tty->ctrl_status |= TIOCPKT_FLUSHREAD; + spin_unlock_irqrestore(&tty->ctrl_lock, flags); if (waitqueue_active(&tty->link->read_wait)) wake_up_interruptible(&tty->link->read_wait); } - spin_unlock_irqrestore(&tty->ctrl_lock, flags); } /** @@ -2128,7 +2129,6 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, int minimum, time; ssize_t retval = 0; long timeout; - unsigned long flags; int packet; c = job_control(tty, file); @@ -2169,15 +2169,20 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, add_wait_queue(&tty->read_wait, &wait); while (nr) { + /* This statement must be first before checking for input + so that any interrupt will set the state back to + TASK_RUNNING. */ + set_current_state(TASK_INTERRUPTIBLE); + /* First test for status change. */ if (packet && tty->link->ctrl_status) { unsigned char cs; if (b != buf) break; - spin_lock_irqsave(&tty->link->ctrl_lock, flags); + spin_lock_irq(&tty->link->ctrl_lock); cs = tty->link->ctrl_status; tty->link->ctrl_status = 0; - spin_unlock_irqrestore(&tty->link->ctrl_lock, flags); + spin_unlock_irq(&tty->link->ctrl_lock); if (tty_put_user(tty, cs, b++)) { retval = -EFAULT; b--; @@ -2186,10 +2191,6 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, nr--; break; } - /* This statement must be first before checking for input - so that any interrupt will set the state back to - TASK_RUNNING. */ - set_current_state(TASK_INTERRUPTIBLE); if (((minimum - (b - buf)) < ldata->minimum_to_wake) && ((minimum - (b - buf)) >= 1)) @@ -2197,46 +2198,30 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, if (!input_available_p(tty, 0)) { if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) { - up_read(&tty->termios_rwsem); - tty_flush_to_ldisc(tty); - down_read(&tty->termios_rwsem); - if (!input_available_p(tty, 0)) { - retval = -EIO; - break; - } - } else { - if (tty_hung_up_p(file)) - break; - if (!timeout) - break; - if (file->f_flags & O_NONBLOCK) { - retval = -EAGAIN; - break; - } - if (signal_pending(current)) { - retval = -ERESTARTSYS; - break; - } - n_tty_set_room(tty); - up_read(&tty->termios_rwsem); - - timeout = schedule_timeout(timeout); - - down_read(&tty->termios_rwsem); - continue; + retval = -EIO; + break; } - } - __set_current_state(TASK_RUNNING); - - /* Deal with packet mode. */ - if (packet && b == buf) { - if (tty_put_user(tty, TIOCPKT_DATA, b++)) { - retval = -EFAULT; - b--; + if (tty_hung_up_p(file)) + break; + if (!timeout) + break; + if (file->f_flags & O_NONBLOCK) { + retval = -EAGAIN; break; } - nr--; + if (signal_pending(current)) { + retval = -ERESTARTSYS; + break; + } + n_tty_set_room(tty); + up_read(&tty->termios_rwsem); + + timeout = schedule_timeout(timeout); + + down_read(&tty->termios_rwsem); + continue; } + __set_current_state(TASK_RUNNING); if (ldata->icanon && !L_EXTPROC(tty)) { retval = canon_copy_from_read_buf(tty, &b, &nr); @@ -2247,8 +2232,17 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, break; } else { int uncopied; - /* The copy function takes the read lock and handles - locking internally for this case */ + + /* Deal with packet mode. */ + if (packet && b == buf) { + if (tty_put_user(tty, TIOCPKT_DATA, b++)) { + retval = -EFAULT; + b--; + break; + } + nr--; + } + uncopied = copy_from_read_buf(tty, &b, &nr); uncopied += copy_from_read_buf(tty, &b, &nr); if (uncopied) { |