linux-kernel - Re: [PATCH v2] regulator: wm8994: Don't use devres for enable GPIOs

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Date:   Thu, 22 Nov 2018 17:21:41 +0000
From:   Charles Keepax <ckeepax@...nsource.cirrus.com>
To:     Linus Walleij <linus.walleij@...aro.org>
CC:     Mark Brown <broonie@...nel.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        <patches@...nsource.cirrus.com>
Subject: Re: [PATCH v2] regulator: wm8994: Don't use devres for enable GPIOs

On Thu, Nov 22, 2018 at 04:47:20PM +0100, Linus Walleij wrote:
> On Thu, Nov 22, 2018 at 3:19 PM Linus Walleij <linus.walleij@...aro.org> wrote:
> > On Wed, Nov 21, 2018 at 11:13 AM Charles Keepax
> > <ckeepax@...nsource.cirrus.com> wrote:
> >
> > > The regulator core takes over managing the lifetime of the enable GPIO
> > > once the regulator is registered. As such we shouldn't register the
> > > enable GPIO using devm, or it will be freed twice.
> > >
> > > Reported-by: Marek Szyprowski <m.szyprowski@...sung.com>
> > > Signed-off-by: Charles Keepax <ckeepax@...nsource.cirrus.com>
> >
> > Reviewed-by: Linus Walleij <linus.walleij@...aro.org>
> 
> Oh no this is not the right solution I think.
> 

Yes I agree I actually am just about to send another series, I
guess I will send that and we can look at that and any
suggestions you have.

> All drivers passing a descriptor (config->ena_gpiod) do their
> own refcounting, including some using a function that has no
> non-devm* counterpart.
> 
> It is better if we teach the core to not gpiod_put() those.
> 

Yeah that is exactly what my patch chain is doing.

> The other patch series I am floating to get rid of the legacy
> GPIO handling from the core will do away with all the
> legacy GPIO handling anyway, so let me introduce a bit
> of ugliness (that can be backported) and then delete that
> ugliness with an updated series v8 of my legacy GPIO
> cleanup.
> 
> Sorry for the inconvenience.
> 
> Will send a patch soon.
> 
> Yours,
> Linus Walleij

Thanks,
Charles