diff options
Diffstat (limited to 'drivers/tty/n_tty.c')
| -rw-r--r-- | drivers/tty/n_tty.c | 25 |
1 files changed, 11 insertions, 14 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index dd8ae0cad1d5..c9a9ddd1d0bc 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -2122,6 +2122,17 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, if (c < 0) return c; + /* + * Internal serialization of reads. + */ + if (file->f_flags & O_NONBLOCK) { + if (!mutex_trylock(&ldata->atomic_read_lock)) + return -EAGAIN; + } else { + if (mutex_lock_interruptible(&ldata->atomic_read_lock)) + return -ERESTARTSYS; + } + down_read(&tty->termios_rwsem); minimum = time = 0; @@ -2141,20 +2152,6 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, } } - /* - * Internal serialization of reads. - */ - if (file->f_flags & O_NONBLOCK) { - if (!mutex_trylock(&ldata->atomic_read_lock)) { - up_read(&tty->termios_rwsem); - return -EAGAIN; - } - } else { - if (mutex_lock_interruptible(&ldata->atomic_read_lock)) { - up_read(&tty->termios_rwsem); - return -ERESTARTSYS; - } - } packet = tty->packet; add_wait_queue(&tty->read_wait, &wait); |