Re: [PATCH 5.10 081/290] gpiolib: Read "gpio-line-names" from a firmware node

From: Greg KH
Date: Wed Mar 17 2021 - 12:07:16 EST


On Mon, Mar 15, 2021 at 05:32:09PM +0100, Bartosz Golaszewski wrote:
> On Mon, Mar 15, 2021 at 4:01 PM Marek Vasut <marex@xxxxxxx> wrote:
> >
> > On 3/15/21 2:52 PM, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
> > > From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > >
> > > From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> > >
> > > commit b41ba2ec54a70908067034f139aa23d0dd2985ce upstream.
> > >
> > > 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.
> >
> > There seem to be some discussion going on around this patch, so please
> > postpone backporting until that is settled. Same for v5.11 backport. I
> > hope Andy/Bartosz agrees ?
>
> Yes, this patch broke at least the testing module and we're working to
> determine if it breaks DT drivers too.

Now dropped, thanks.

greg k-h