Re: [PATCH] gpiolib: acpi: Fix failed in acpi_gpiochip_find() by adding parent node match

[Mika Westerberg]

On Mon, May 13, 2024 at 03:59:01PM +0800, Devyn Liu wrote:
> Previous patch modified the standard used by acpi_gpiochip_find()
> to match device nodes. Using the device node set in gc->gpiodev->d-
> ev instead of gc->parent.
> 
> However, there is a situation in gpio-dwapb where the GPIO device
> driver will set gc->fwnode for each port corresponding to a child
> node under a GPIO device, so gc->gpiodev->dev will be assigned the
> value of each child node in gpiochip_add_data().
> 
> gpio-dwapb.c:
> 128,31 static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
> 			       struct dwapb_port_property *pp,
> 			       unsigned int offs);
> port->gc.fwnode = pp->fwnode;
> 
> 693,39 static int dwapb_gpio_probe;
> err = dwapb_gpio_add_port(gpio, &pdata->properties[i], i);
> 
> When other drivers request GPIO pin resources through the GPIO device
> node provided by ACPI (corresponding to the parent node), the change
> of the matching object to gc->gpiodev->dev in acpi_gpiochip_find()
> only allows finding the value of each port (child node), resulting
> in a failed request.
> 
> Reapply the condition of using gc->parent for match in acpi_gpio-
> chip_find() in the code can compatible with the problem of gpio-dwapb,
> and will not affect the two cases mentioned in the patch:
> 1. There is no setting for gc->fwnode.
> 2. The case that depends on using gc->fwnode for match.
> 
> Fixes: 5062e4c14b75 ("gpiolib: acpi: use the fwnode in acpi_gpiochip_find()")
> Fixes: 067dbc1ea5ce ("gpiolib: acpi: Don't use GPIO chip fwnode in acpi_gpiochip_find()")
> Signed-off-by: Devyn Liu <liudingyuan@xxxxxxxxxx>

Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>