Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 20 Nov 2023 08:21:46 +0100 | Subject | Re: [Patch v8 1/6] tty: add new helper function tty_get_tiocm | From | Jiri Slaby <> |
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On 09. 11. 23, 9:50, Florian Eckert wrote: > There is no in-kernel function to get the status register of a tty device > like the TIOCMGET ioctl returns to userspace. Create a new function, > tty_get_tiocm(), to obtain the status register that other portions of the > kernel can call if they need this information, and move the existing > internal tty_tiocmget() function to use this interface. > > Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Signed-off-by: Florian Eckert <fe@dev.tdt.de> > --- > drivers/tty/tty_io.c | 28 ++++++++++++++++++++++------ > include/linux/tty.h | 1 + > 2 files changed, 23 insertions(+), 6 deletions(-) > > diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c > index 06414e43e0b5..e2e93404133e 100644 > --- a/drivers/tty/tty_io.c > +++ b/drivers/tty/tty_io.c > @@ -2498,6 +2498,24 @@ static int send_break(struct tty_struct *tty, unsigned int duration) > return retval; > } > > +/** > + * tty_get_tiocm - get tiocm status register > + * @tty: tty device > + * > + * Obtain the modem status bits from the tty driver if the feature > + * is supported. > + */ > +int tty_get_tiocm(struct tty_struct *tty) > +{ > + int retval = -ENOTTY; > + > + if (tty->ops->tiocmget) > + retval = tty->ops->tiocmget(tty); > + > + return retval;
Why not simply: { if (tty->ops->tiocmget) return tty->ops->tiocmget(tty);
return -ENOTTY; } ?
thanks, -- js suse labs
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