On Thu, Jun 11, 2015 at 10:23:17AM +0200, Linus Walleij wrote:
> On Wed, Jun 10, 2015 at 8:23 PM, Uwe Kleine-König
> <u.kleine-koenig@xxxxxxxxxxxxxx> wrote:
>
> > Hello,
> >
> > I just noticed that drivers/tty/serial/etraxfs-uart.c (introduced in
> > commit 692132b5b1c5 (serial: driver for ETRAX FS UART) for 4.0-rc1)
> > doesn't use the gpiod stuff correctly and does strange things with the
> > modem status lines. In etraxfs_uart_probe it calls
> >
> > up->dtr_pin = devm_gpiod_get_optional(&pdev->dev, "dtr");
> >
> > without further checking of the result. The only other usage of the
> > dtr_pin member is:
> >
> > static unsigned int etraxfs_uart_get_mctrl(struct uart_port *port)
> > {
> > ...
> > if (up->dtr_pin && !gpiod_get_raw_value(up->dtr_pin))
> > ret |= TIOCM_DTR;
> > ...
> > }
> >
> > and a similar construct in .set_mctrl.
> >
> > There are several problems:
> >
> > - get_mctrl isn't about DTR;
> > - the dtr_pin gpiod doesn't have a direction set;
> > - devm_gpiod_get_optional might return ERR_PTR(-ESOMETHING) and
> > gpiod_get_raw_value isn't able to handle that; and
> > - instead of explicitly coding gpio mctrl lines, serial_mctrl_gpio
> > should be used.
> >
> > The other 3 gpiods requested have similar problems.
My guess is that this is all theoretical code. CRIS does not have gpiolib
support (yet), and the code is probably a placeholder for the DTR functionality
from the old crappy driver.
> > Who cares for that?
I've poked Niklas, but since he's on vacation now, I'm not sure if
he'll have time to fix this.
I can push a patch that just drops all signal handling (since it's bogus ATM),
or you can ignore the driver as currently implemented.
> I bet sending the remark to the driver writers and random Axis/ETRAX
> people is going to help ;) (see To: line)
:-)
> Yours,
> Linus Walleij
/^JN - Jesper Nilsson
--
Jesper Nilsson -- jesper.nilsson@xxxxxxxx
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