Re: [PATCH 2/4] iio: light: stk3310: Implement vdd supply and power it off during suspend

From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Aren <aren@peacevolution.org>
Cc: "Jonathan Cameron" <jic23@kernel.org>,
	"Lars-Peter Clausen" <lars@metafoo.de>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Chen-Yu Tsai" <wens@csie.org>,
	"Jernej Skrabec" <jernej.skrabec@gmail.com>,
	"Samuel Holland" <samuel@sholland.org>,
	"Liam Girdwood" <lgirdwood@gmail.com>,
	"Mark Brown" <broonie@kernel.org>, "Ondrej Jirman" <megi@xff.cz>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	linux-iio@vger.kernel.org, phone-devel@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-sunxi@lists.linux.dev,
	"Willow Barraco" <contact@willowbarraco.fr>
Subject: Re: [PATCH 2/4] iio: light: stk3310: Implement vdd supply and power it off during suspend
Date: Thu, 18 Apr 2024 18:56:09 +0300	[thread overview]
Message-ID: <CAHp75Veoibnk2pYuAY-T+u=8t7ackQ8zBjxSHcWb1AeHnq84yQ@mail.gmail.com> (raw)
In-Reply-To: <xxeg3as5m5vmmu6fbjujcnvchrerxs2rr42nloirwsktbv4r57@vpxtxblxmspl>

On Thu, Apr 18, 2024 at 6:06 PM Aren <aren@peacevolution.org> wrote:
> On Mon, Apr 15, 2024 at 05:04:53PM +0300, Andy Shevchenko wrote:
> > On Sun, Apr 14, 2024 at 8:57 PM Aren Moynihan <aren@peacevolution.org> wrote:

...

> > >         stk3310_set_state(iio_priv(indio_dev), STK3310_STATE_STANDBY);
> > > +       if (data->vdd_reg)
> > > +               regulator_disable(data->vdd_reg);
> >
> > I forgot to check the order of freeing resources, be sure you have no
> > devm_*() releases happening before this call.
>
> If I understand what you're saying, this should be fine. The driver just
> uses devm to clean up acquired resources after remove is called. Or am I
> missing something and resources could be freed before calling
> stk3310_remove?

I'm not objecting to that. The point here is that the resources should
be freed in the reversed order. devm-allocated resources are deferred
to be freed after the explicit driver ->remove() callback. At the end
it should not interleave with each other, i.o.w. it should be
probe: devm followed by non-devm
remove: non-devm only.

-- 
With Best Regards,
Andy Shevchenko