Re: [PATCH v1 1/1] gpiolib: Read "gpio-line-names" from a firmware node

[Marek Vasut]

On 3/5/21 1:24 PM, Andy Shevchenko wrote:
> On Fri, Mar 05, 2021 at 01:11:39PM +0100, Marek Vasut wrote:
> > On 3/5/21 1:02 PM, Andy Shevchenko wrote:
> > > On STM32MP1, the GPIO banks are subnodes of pin-controller@50002000,
> > > see arch/arm/boot/dts/stm32mp151.dtsi. The driver for
> > > pin-controller@50002000 is in drivers/pinctrl/stm32/pinctrl-stm32.c
> > > and iterates over all of its DT subnodes when registering each GPIO
> > > bank gpiochip. Each gpiochip has:
> > >
> > >     - gpio_chip.parent = dev,
> > >       where dev is the device node of the pin controller
> > >     - gpio_chip.of_node = np,
> > >       which is the OF node of the GPIO bank
> > >
> > > Therefore, dev_fwnode(chip->parent) != of_fwnode_handle(chip.of_node),
> > > i.e. pin-controller@50002000 != pin-controller@50002000/gpio@5000*000.
> > >
> > > The original code behaved correctly, as it extracted the "gpio-line-names"
> > > from of_fwnode_handle(chip.of_node) = pin-controller@50002000/gpio@5000*000.
> > >
> > > To achieve the same behaviour, read property from the firmware node.
> > >
> > > Fixes: 7cba1a4d5e162 ("gpiolib: generalize devprop_gpiochip_set_names() for device properties")
> > > Reported-by: Marek Vasut <marex@xxxxxxx>
> > > Reported-by: Roman Guskov <rguskov@xxxxxxxxxxxxxxxxxx>
> > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> >
> > Tested-by: Marek Vasut <marex@xxxxxxx>
> > Reviewed-by: Marek Vasut <marex@xxxxxxx>
>
> Thanks!
>
> > Thanks
> >
> > >    static int devprop_gpiochip_set_names(struct gpio_chip *chip)
> > >    {
> > >    	struct gpio_device *gdev = chip->gpiodev;
> > > -	struct device *dev = chip->parent;
> > > +	struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
> >
> > You could make the order here a reverse xmas tree, but that's a nitpick.
>
> They are dependent, can't be reordered.

Doh, you're right.