Messages in this thread | | | Date | Tue, 21 Nov 2023 08:35:11 +0100 | From | Florian Eckert <> | Subject | Re: [Patch v8 1/6] tty: add new helper function tty_get_tiocm |
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On 2023-11-20 08:21, Jiri Slaby wrote: > 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:
I just did it this way because it is also done this way in other functions in this file.
> { > if (tty->ops->tiocmget) > return tty->ops->tiocmget(tty); > > return -ENOTTY; > }
Of course, we could also do it this way. If this is the C style for the kernel, then I will change it. Please give me a short feedback whether I should change it and send a v9, or whether it is just a comment from you.
Best regards
Florian
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