Messages in this thread | | | Date | Wed, 1 Oct 2014 12:13:09 +0300 | From | Mika Westerberg <> | Subject | Re: [PATCH v3 10/15] leds: leds-gpio: Add ACPI probing support |
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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, > > (or whatever you want to call it).
That's a good idea.
> Regarding the MODULE_DEVICE_TABLE, I suspect the above won't work the > way you are hoping for, because once you get to dozens or hundreds of > drivers doing this, each device will show up with the same string, > so udev will try to load all the modules that list "PRP0001". That > doesn't look right. With the code from patch 3, you can probably drop > the acpi MODULE_DEVICE_TABLE() entirely and get the correct behavior.
It actually works like this now:
# cd /sys/bus/platform/devices/PRP0001\:00/ DRIVER=leds-gpio MODALIAS=of:Nprp0001TacpiCgpio-leds
# cat modalias of:Nprp0001TacpiCgpio-leds
In other words the modalias changes to be of:Nprp0001Tacpi, e.g name=prp0001, type=acpi and then list of compatible values.
Udev then loads only module that matches the modalias so it should not load everything listing PRP0001 in their MODULE_DEVICE_TABLE().
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