diff options
| -rw-r--r-- | drivers/char/tty_ioctl.c | 19 | ||||
| -rw-r--r-- | drivers/usb/serial/pl2303.c | 7 | ||||
| -rw-r--r-- | include/linux/tty.h | 1 |
3 files changed, 27 insertions, 0 deletions
diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c index e02d59245a17..d4b6d64e858b 100644 --- a/drivers/char/tty_ioctl.c +++ b/drivers/char/tty_ioctl.c @@ -365,6 +365,25 @@ void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old) EXPORT_SYMBOL(tty_termios_copy_hw); /** + * tty_termios_hw_change - check for setting change + * @a: termios + * @b: termios to compare + * + * Check if any of the bits that affect a dumb device have changed + * between the two termios structures, or a speed change is needed. + */ + +int tty_termios_hw_change(struct ktermios *a, struct ktermios *b) +{ + if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed) + return 1; + if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL)) + return 1; + return 0; +} +EXPORT_SYMBOL(tty_termios_hw_change); + +/** * change_termios - update termios values * @tty: tty to update * @new_termios: desired new value diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c index cf8add91de05..0da1df9c79bf 100644 --- a/drivers/usb/serial/pl2303.c +++ b/drivers/usb/serial/pl2303.c @@ -483,6 +483,13 @@ static void pl2303_set_termios(struct usb_serial_port *port, } spin_unlock_irqrestore(&priv->lock, flags); + /* The PL2303 is reported to lose bytes if you change + serial settings even to the same values as before. Thus + we actually need to filter in this specific case */ + + if (!tty_termios_hw_change(port->tty->termios, old_termios)) + return; + cflag = port->tty->termios->c_cflag; buf = kzalloc(7, GFP_KERNEL); diff --git a/include/linux/tty.h b/include/linux/tty.h index c555f5442bd7..defd2ab72449 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -319,6 +319,7 @@ extern speed_t tty_termios_input_baud_rate(struct ktermios *termios); extern void tty_termios_encode_baud_rate(struct ktermios *termios, speed_t ibaud, speed_t obaud); extern void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud); extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old); +extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b); extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *); extern void tty_ldisc_deref(struct tty_ldisc *); |