Re: [PATCH 01/38] ASoC: ak5558: drop of_match_ptr from of_device_id table

[Andy Shevchenko]

On Mon, Nov 23, 2020 at 03:42:25PM +0200, Andy Shevchenko wrote:
> On Mon, Nov 23, 2020 at 01:41:29PM +0100, Krzysztof Kozlowski wrote:
> > On Mon, Nov 23, 2020 at 12:37:31PM +0000, Mark Brown wrote:
> > > On Mon, Nov 23, 2020 at 12:48:32PM +0200, Andy Shevchenko wrote:
> > > > On Sun, Nov 22, 2020 at 11:59:20AM +0100, Krzysztof Kozlowski wrote:
> > > > > On Fri, Nov 20, 2020 at 08:04:29PM +0000, Mark Brown wrote:
> > > 
> > > > > > Surely if that's the desired outcome the fix is to change the definition
> > > > > > of of_match_ptr() such that it leaves the reference with CONFIG_ACPI,
> > > > > > perhaps hidden behind a config option for PRP0001?  That seems better
> > > > > > than going through the entire tree like this.
> > > 
> > > > > That could be indeed an easier way to achieve this.
> > > 
> > > > ...easier and wrong in my opinion. Not all drivers need that.
> > > > What the point to touch it in the driver which is OF-only?
> > > > (For IP which will quite unlikely to be present in ACPI world)
> > > > Or if the device will get the correct ACPI ID?
> > > 
> > > That feels like something that should be done with Kconfig dependencies
> > > like a direct OF dependency (possibly a !PRP0001 dependency?) for the
> > > driver or possibly with having a variant of_match_ptr() for things that
> > > really don't want to support PRP0001.  Just removing all the use of
> > > of_match_ptr() is both noisy and confusing in that it looks like it's
> > > creating issues to fix, it makes it hard to understand when and why one
> > > should use the macro.
> > 
> > For the OF-only drivers (without other ID table), there is no point to
> > use the macro. Driver can bind only with DT, so what is the point of
> > of_match_ptr? To skip the OF table when building without OF? Driver
> > won't be usable at all in such case. So maybe for compile testing?
> > There is no need to remove OF table for simple build tests.
> 
> I'm on the same page here.

I should have elaborated that under OF only I meant rather !ACPI. So, when it
has no ID tables, I agree that macro is not needed. But, for instance, I²C
device drivers tend to have table even for ->probe_new() callback to be able to
instantiate them via user space.

-- 
With Best Regards,
Andy Shevchenko