2015-01-25 19:44:54

by Peter Hurley

Subject: [PATCH 4/4] tty: Remove external interface for tty_set_termios()

tty_set_termios() is an internal helper intended for file scope use.

UART drivers which are capable of driving the RTS pin must
properly handle the tiocmset() method, regardless of termios settings.
A failure to do so is a UART driver bug and should be fixed there.
Do not use this interface to workaround UART driver bugs.

Cc: Marcel Holtmann <[email protected]>
Cc: Johan Hedberg <[email protected]>
Cc: <[email protected]>
Signed-off-by: Peter Hurley <[email protected]>
---
drivers/bluetooth/hci_ath.c | 15 ++-------------
drivers/tty/tty_ioctl.c | 3 +--
include/linux/tty.h | 1 -
3 files changed, 3 insertions(+), 16 deletions(-)

diff --git a/drivers/bluetooth/hci_ath.c b/drivers/bluetooth/hci_ath.c
index 2ff6dfd..9c4dcf4 100644
--- a/drivers/bluetooth/hci_ath.c
+++ b/drivers/bluetooth/hci_ath.c
@@ -51,33 +51,22 @@ struct ath_struct {

static int ath_wakeup_ar3k(struct tty_struct *tty)
{
- struct ktermios ktermios;
int status = tty->driver->ops->tiocmget(tty);

if (status & TIOCM_CTS)
return status;

- /* Disable Automatic RTSCTS */
- ktermios = tty->termios;
- ktermios.c_cflag &= ~CRTSCTS;
- tty_set_termios(tty, &ktermios);
-
/* Clear RTS first */
- status = tty->driver->ops->tiocmget(tty);
+ tty->driver->ops->tiocmget(tty);
tty->driver->ops->tiocmset(tty, 0x00, TIOCM_RTS);
mdelay(20);

/* Set RTS, wake up board */
- status = tty->driver->ops->tiocmget(tty);
+ tty->driver->ops->tiocmget(tty);
tty->driver->ops->tiocmset(tty, TIOCM_RTS, 0x00);
mdelay(20);

status = tty->driver->ops->tiocmget(tty);
-
- /* Enable Automatic RTSCTS */
- ktermios.c_cflag |= CRTSCTS;
- status = tty_set_termios(tty, &ktermios);
-
return status;
}

diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
index d73f695..69fc0b8 100644
--- a/drivers/tty/tty_ioctl.c
+++ b/drivers/tty/tty_ioctl.c
@@ -533,7 +533,7 @@ EXPORT_SYMBOL(tty_termios_hw_change);
* Locking: termios_rwsem
*/

-int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
+static int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
{
struct ktermios old_termios;
struct tty_ldisc *ld;
@@ -566,7 +566,6 @@ int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
up_write(&tty->termios_rwsem);
return 0;
}
-EXPORT_SYMBOL_GPL(tty_set_termios);

/**
* set_termios - set termios values for a tty
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 0992238..8c316b6 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -491,7 +491,6 @@ static inline speed_t tty_get_baud_rate(struct tty_struct *tty)

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 int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);

extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
extern void tty_ldisc_deref(struct tty_ldisc *);
--
2.2.2

2015-01-25 20:36:32

by Marcel Holtmann

Subject: Re: [PATCH 4/4] tty: Remove external interface for tty_set_termios()

Hi Peter,

> tty_set_termios() is an internal helper intended for file scope use.
>
> UART drivers which are capable of driving the RTS pin must
> properly handle the tiocmset() method, regardless of termios settings.
> A failure to do so is a UART driver bug and should be fixed there.
> Do not use this interface to workaround UART driver bugs.
>
> Cc: Marcel Holtmann <[email protected]>
> Cc: Johan Hedberg <[email protected]>
> Cc: <[email protected]>
> Signed-off-by: Peter Hurley <[email protected]>
> ---
> drivers/bluetooth/hci_ath.c | 15 ++-------------
> drivers/tty/tty_ioctl.c | 3 +--
> include/linux/tty.h | 1 -
> 3 files changed, 3 insertions(+), 16 deletions(-)

I think the less complication is if this goes through the TTY tree.

Acked-by: Marcel Holtmann <[email protected]>

Regards

Marcel