Re: [PATCH 2/2] USB: serial: cp210x: add gpio-configuration debug printk

Andy Shevchenko
2021-04-09T16:22:47Z

On Fri, Apr 9, 2021 at 6:52 PM Johan Hovold <johan@kernel.org> wrote:
>
> Add a debug printk to dump the GPIO configuration stored in EEPROM
> during probe.
>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
> drivers/usb/serial/cp210x.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
> index ceb3a656a075..ee595d1bea0a 100644
> --- a/drivers/usb/serial/cp210x.c
> +++ b/drivers/usb/serial/cp210x.c
> @@ -1543,10 +1543,16 @@ static int cp210x_gpio_init_valid_mask(struct gpio_chip *gc,
> {
> struct usb_serial *serial = gpiochip_get_data(gc);
> struct cp210x_serial_private *priv = usb_get_serial_data(serial);
> + struct device *dev = &serial->interface->dev;
> unsigned long altfunc_mask = priv->gpio_altfunc;
>
> bitmap_complement(valid_mask, &altfunc_mask, ngpios);
>
> + if (bitmap_empty(valid_mask, ngpios))
> + dev_dbg(dev, "no pin configured for GPIO\n");

Shouldn't we drop the GPIO device completely in such a case?
Bart, wouldn't it be a good idea for GPIO library to do something like
this on driver's behalf?

> + else
> + dev_dbg(dev, "GPIO.%*pbl configured for GPIO\n", ngpios,
> + valid_mask);

A nit-pick:
I would change GPIO -> pin in the second message in the first occurrence.

> return 0;
> }
>
> --
> 2.26.3
>

--
With Best Regards,
Andy Shevchenko