linux-kernel - Re: [PATCH v1 1/5] regmap: mmio: Don't unprepare attached clock

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Message-ID: <CAHp75VfL2kKqP5m1SZfBdd0Z-kLg=rcccAxmQ4LOd88gOuFcww@mail.gmail.com>
Date:   Mon, 8 Aug 2022 20:23:28 +0200
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Mark Brown <broonie@...nel.org>
Cc:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Aidan MacDonald <aidanmacdonald.0x0@...il.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>
Subject: Re: [PATCH v1 1/5] regmap: mmio: Don't unprepare attached clock

On Mon, Aug 8, 2022 at 5:52 PM Mark Brown <broonie@...nel.org> wrote:
> On Mon, Aug 08, 2022 at 04:42:28PM +0200, Andy Shevchenko wrote:
> > On Mon, Aug 8, 2022 at 3:48 PM Mark Brown <broonie@...nel.org> wrote:
> > > On Mon, Aug 08, 2022 at 03:41:48PM +0200, Andy Shevchenko wrote:
> > > > On Mon, Aug 8, 2022 at 3:19 PM Mark Brown <broonie@...nel.org> wrote:
>
> > > > > regmap_mmio_attach_clk() prepares the clock that's passed in, we should
> > > > > undo that when detaching otherwise we're leaking a prepare (as we do in
> > > > > the explicit detach).
>
> > > > Why do we allow the user to avoid explicit detach? What is the point
> > > > of having that API in the case we take care of it?
>
> > > I think just for symmetry so it's obvious that error handling is
> > > happening if people want it to be.
>
> > So, the only user of that API calls it explicitly. Should I rewrite a
> > commit message somehow?
>
> No.  Your commit would just introduce a bug.

There is no bug with the existing codebase after this commit. Are you
talking about out-of-tree modules? Or maybe there is documentation
that says that regmap clears all additionally attached resources?

Okay I may admit that Fixes tag might be wrong due to potential users
in the past. However, in the current state of affairs either we can
proceed with a patch, or amend documentation (if not yet done) to
clarify this aspect of regmap MMIO. From the above I may assume that
you would rather expect the latter to be done (if not yet).

-- 
With Best Regards,
Andy Shevchenko