Re: [PATCH v3 10/15] leds: leds-gpio: Add ACPI probing support

[Dmitry Torokhov]

On Wed, Oct 01, 2014 at 11:11:46AM -0700, Darren Hart wrote:
> On 10/1/14, 9:30, "Dmitry Torokhov" <dmitry.torokhov@xxxxxxxxx> wrote:
> 
> >On Wed, Oct 01, 2014 at 10:13:04AM +0200, Arnd Bergmann wrote:
> >> On Wednesday 01 October 2014 04:17:02 Rafael J. Wysocki wrote:
> >> > Index: linux-pm/drivers/leds/leds-gpio.c
> >> > ===================================================================
> >> > --- linux-pm.orig/drivers/leds/leds-gpio.c
> >> > +++ linux-pm/drivers/leds/leds-gpio.c
> >> > @@ -231,6 +231,13 @@ static const struct of_device_id of_gpio
> >> >  
> >> >  MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
> >> >  
> >> > +static const struct acpi_device_id acpi_gpio_leds_match[] = {
> >> > +       { "PRP0001" }, /* Device Tree shoehorned into ACPI */
> >> > +       {},
> >> > +};
> >> > +
> >> > +MODULE_DEVICE_TABLE(acpi, acpi_gpio_leds_match);
> >> > +
> >> >  static int gpio_led_probe(struct platform_device *pdev)
> >> >  {
> >> >         struct gpio_led_platform_data *pdata =
> >>dev_get_platdata(&pdev->dev);
> >> > @@ -286,6 +293,7 @@ static struct platform_driver gpio_led_d
> >> >                 .name   = "leds-gpio",
> >> >                 .owner  = THIS_MODULE,
> >> >                 .of_match_table = of_gpio_leds_match,
> >> > +               .acpi_match_table = acpi_gpio_leds_match,
> >> >         },
> >> >  };
> >> 
> >> Is this something you'd have to do in every driver you want to support
> >> _PRP based probing? For the ".acpi_match_table =" reference, I think
> >> you could actually provide a generic acpi_device_id table exported from
> >> core code that you refer to, so each driver just does
> >> 
> >> 	.acpi_match_table = acpi_match_by_of_compatible,
> >
> >No, I think in absence of drv->acpi_match_table ACPI core should just go
> >and
> >use drv->of_match_table to do the matching and be done with it.
> 
> But then you will match drivers that have of-only support that don't know
> anything about ACPI and haven't been updated to use the new API. Worse,
> some of those drivers will assume of node structs and such and potentially
> panic. Unless I'm sorry mistaken here....

Does ACPI set dev->of_node pointer? I'd expect them to fail right there...

-- 
Dmitry
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