Message-ID: <1503304689.8125.6.camel@pengutronix.de>
Subject: Re: [PATCH v3 3/5] reset: stm32: use the reset-simple driver
From: Philipp Zabel <p.zabel@pengutronix.de>
To: Andre Przywara <andre.przywara@arm.com>,
        Alexandru Gagniuc <alex.g@adaptrum.com>,
        Andreas =?ISO-8859-1?Q?F=E4rber?= <afaerber@suse.de>
Cc: linux-kernel@vger.kernel.org,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        Maxime Ripard <maxime.ripard@free-electrons.com>,
        Chen-Yu Tsai <wens@csie.org>, Baoyou Xie <baoyou.xie@linaro.org>,
        Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>,
        Steffen Trumtrar <s.trumtrar@pengutronix.de>,
        Dinh Nguyen <dinguyen@kernel.org>,
        linux-arm-kernel@lists.infradead.org, kernel@pengutronix.de
Date: Mon, 21 Aug 2017 10:38:09 +0200
In-Reply-To: <74144e84-cd37-511a-9702-ceb590f37bf0@arm.com>
References: <20170816094701.30678-1-p.zabel@pengutronix.de>
         <20170816094701.30678-4-p.zabel@pengutronix.de>
         <edbdf06c-fb1e-63f1-d6b2-17193c86385a@adaptrum.com>
         <338608e8-9e83-fc0f-8d8a-18a336e94860@suse.de>
         <d46ad9ea-4bf5-5ceb-cfc8-0c1efa48bb02@adaptrum.com>
         <74144e84-cd37-511a-9702-ceb590f37bf0@arm.com>
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On Thu, 2017-08-17 at 10:19 +0100, Andre Przywara wrote:
> Hi,
> 
> On 16/08/17 21:55, Alexandru Gagniuc wrote:
> > 
> > 
> > On 08/16/2017 01:52 PM, Andreas Färber wrote:
> > > Am 16.08.2017 um 22:50 schrieb Alexandru Gagniuc:
> > > > On 08/16/2017 02:46 AM, Philipp Zabel wrote:
> > > > > The reset-simple driver can be used without changes.
> > > > > 
> > > > > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> > > > 
> > > > > > > > Reviewed-by: Alexandru Gagniuc <alex.g@adaptrum.com>
> > > > 
> > > > > ---
> > > > >  drivers/reset/Kconfig        |  11 ++---
> > > > >  drivers/reset/Makefile       |   1 -
> > > > >  drivers/reset/reset-simple.c |   1 +
> > > > >  drivers/reset/reset-stm32.c  | 108
> > > > > -------------------------------------------
> > > > >  4 files changed, 4 insertions(+), 117 deletions(-)
> > > > >  delete mode 100644 drivers/reset/reset-stm32.c
> > > > > 
> > > > > diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> > > > > index 78a8f6057985b..29f4487c290fc 100644
> > > > > --- a/drivers/reset/Kconfig
> > > > > +++ b/drivers/reset/Kconfig
> > > > > @@ -70,19 +70,14 @@ config RESET_PISTACHIO
> > > > > 
> > > > >  config RESET_SIMPLE
> > > > >      bool "Simple Reset Controller Driver" if COMPILE_TEST
> > > > > -    default ARCH_SOCFPGA || ARCH_SUNXI
> > > > > +    default ARCH_SOCFPGA || ARCH_STM32 || ARCH_SUNXI
> > > > 
> > > > If this series gets respun, could you please look into removing the
> > > > ARCH_ dependency here?
> > > 
> > > Why?
> > 
> > Because the driver has to keep track of all its users, which is a
> > layering violation.
> 
> "keep track of all its users": not necessarily, this is mostly for
> convenience reasons to get automatic coverage for those SoCs without
> changing various defconfigs - or distribution .configs, for that matter.
> Especially the latter may prove to be nasty and introduce regressions.
> 
> But I see that this list may grow big and this is a bit beyond the scope
> of the otherwise neat "default ARCH_xxx" trick.
> 
> So given the generic nature of this driver, can't we make this simply:
> "default ARM || ARM64"
> That would enable it everywhere automatically, but people can still
> disable this if they know what they do.
> 
> Alternatively for ARM64 this is actually a candidate for the (one and
> only) defconfig.

I would like to make this driver selectable. but for that to happen,
ARCH_HAS_RESET_CONTROLLER and RESET_CONTROLLER have to be merged into a
single selectable symbol first.

Until then, I'd be fine with making this driver:
	bool "Simple Reset Controller Driver"
	default ARM || ARM64 
but in my opinion it is equally ok to have the default ARCH_* list for
a while.

regards
Philipp