Re: [PATCH 3/6] net: stmmac: sun8i: Use devm_regulator_get for PHY regulator

[OndÅej Jirman]

Hi Andrew,

On Tue, Aug 20, 2019 at 05:39:39PM +0200, Andrew Lunn wrote:
> On Tue, Aug 20, 2019 at 04:53:40PM +0200, megous@xxxxxxxxxx wrote:
> > From: Ondrej Jirman <megous@xxxxxxxxxx>
> > 
> > Use devm_regulator_get instead of devm_regulator_get_optional and rely
> > on dummy supply. This avoids NULL checks before regulator_enable/disable
> > calls.
> 
> Hi Ondrej
> 
> What do you mean by a dummy supply? I'm just trying to make sure you
> are not breaking backwards compatibility.

Sorry, I mean dummy regulator. See:

https://elixir.bootlin.com/linux/latest/source/drivers/regulator/core.c#L1874

On systems that use DT (i.e. have_full_constraints() == true), when the
regulator is not found (ENODEV, not specified in DT), regulator_get will return
a fake dummy regulator that can be enabled/disabled, but doesn't do anything
real.

This can be used to avoid NULL checks and make the code simpler.

regards,
	Ondrej

>      Thanks
> 	Andrew