Re: [PATCH v3 1/2] driver: reset: spacemit-p1: add driver for poweroff/reboot

From: Troy Mitchell <troy.mitchell@linux.spacemit.com>
To: Yixun Lan <dlan@gentoo.org>,
	linux-kernel@vger.kernel.org, Lee Jones <lee@kernel.org>,
	Sebastian Reichel <sre@kernel.org>,
	Troy Mitchell <troy.mitchell@linux.spacemit.com>,
	Paul Walmsley <pjw@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Alexandre Ghiti <alex@ghiti.fr>,
	"open list:RISC-V ARCHITECTURE:Keyword:riscv"
	<linux-riscv@lists.infradead.org>,
	"open list:RISC-V SPACEMIT SoC Support:Keyword:spacemit"
	<spacemit@lists.linux.dev>,
	"open list:SYSTEM RESET/SHUTDOWN DRIVERS"
	<linux-pm@vger.kernel.org>
Subject: Re: [PATCH v3 1/2] driver: reset: spacemit-p1: add driver for poweroff/reboot
Date: Wed, 22 Oct 2025 13:42:04 +0800	[thread overview]
Message-ID: <52468F28CD7B50FD+aPhurJD4HTXqIGDT@kernel.org> (raw)
In-Reply-To: <aPhtd0j6iBpqiGUQ@aurel32.net>

> > > diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
> > > index 8248895ca9038..6577d73edbda4 100644
> > > --- a/drivers/power/reset/Kconfig
> > > +++ b/drivers/power/reset/Kconfig
> > > @@ -283,6 +283,15 @@ config POWER_RESET_KEYSTONE
> > >  	help
> > >  	  Reboot support for the KEYSTONE SoCs.
> > >  
> > > +config POWER_RESET_SPACEMIT_P1
> > > +	tristate "SpacemiT P1 poweroff and reset driver"
> > > +	depends on ARCH_SPACEMIT || COMPILE_TEST
> > ..
> > > +	select MFD_SPACEMIT_P1
> > I'd suggest to use "depends on" instead of "select", the reason is that
> > using "select" will sometimes ignore the dependency, considering
> > the reset driver here is tightly coupled with P1, so I think it's 
> > reasonable to switch to use "depends on", also refer below link
> > 
> > https://lxr.linux.no/#linux+v6.7.1/Documentation/kbuild/kconfig-language.rst#L144
> > 
> >         select should be used with care. select will force
> >         a symbol to a value without visiting the dependencies.
> >         By abusing select you are able to select a symbol FOO even
> >         if FOO depends on BAR that is not set.
> >         In general use select only for non-visible symbols
> >         (no prompts anywhere) and for symbols with no dependencies.
> >         That will limit the usefulness but on the other hand avoid
> >         the illegal configurations all over.
> 
> Thanks for the pointer, I'll fix that in the next version. I used 
> REGULATOR_SPACEMIT_P1 and RTC_DRV_SPACEMIT_P1 as examples, they'll also 
> need to be fixed.
Yes, I have said here[1].
Do you want to fix that? If you don't have time, I can do it.

> 
> Note also that without the select, a default value has to be added to 
> MFD_SPACEMIT_P1. 
Yes, I will add it in my patch. Thanks.

                  - Troy

Link: https://lore.kernel.org/all/6DB8C5F20B3FAC2E+aPhfoRXlJtJymlB5@kernel.org/ [1]

> otherwise this makes the default values on the 
> regulator, rtc and reboot drivers useless.
> 
> -- 
> Aurelien Jarno                          GPG: 4096R/1DDD8C9B
> aurelien@aurel32.net                     http://aurel32.net
>