Re: [PATCH leds v2 05/50] leds: various: guard of_match_table member value with of_match_ptr

From: Marek Behun
Date: Fri Sep 18 2020 - 06:10:11 EST


On Fri, 18 Sep 2020 12:57:59 +0300
Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> wrote:

> On Fri, Sep 18, 2020 at 11:20:58AM +0200, Marek Behun wrote:
> > On Fri, 18 Sep 2020 09:15:00 +0300
> > Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> wrote:
> >
> > > Hi Marek,
> > >
> > > On Fri, Sep 18, 2020 at 12:32:53AM +0200, Marek Behún wrote:
> > > > Change
> > > > .of_match_table = xxx,
> > > > to
> > > > .of_match_table = of_match_ptr(xxx),
> > > > in various drivers.
> > > >
> > > > This should be standard even for drivers that depend on OF.
> > >
> > > After this patch, none of these drivers will work on ACPI systems anymore.
>
> ^
>
> If CONFIG_OF is disabled, that is.
>
> >
> > Hi Sakari,
> >
> > I don't understand. Why not? Does ACPI subsystem parse of_match_table
> > as well?
>
> It does. The compatible string is used the same way as in DT for matching
> devices with "PRP0001" _HID or _CID.
>
> Please read Documentation/firmware-guide/acpi/enumeration.rst .
>
> IOW, you can safely do the above only for drivers that depend on OF in
> Kconfig. Otherwise you'll probably break something.
>

Sakari, thank you for the pointer to the docs.
I thought that of_match_table is used only by OF (hence the name).

Marek