linux-kernel - Re: [PATCH 1/3] clk: qcom: gdsc: add collapse-bit helper

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Message-ID: <YoeDhpCzV2sR7+Y1@hovoldconsulting.com>
Date:   Fri, 20 May 2022 14:03:18 +0200
From:   Johan Hovold <johan@...nel.org>
To:     Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
Cc:     Johan Hovold <johan+linaro@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Andy Gross <agross@...nel.org>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>, linux-arm-msm@...r.kernel.org,
        linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/3] clk: qcom: gdsc: add collapse-bit helper

On Fri, May 20, 2022 at 02:50:17PM +0300, Dmitry Baryshkov wrote:
> On Fri, 20 May 2022 at 13:10, Johan Hovold <johan+linaro@...nel.org> wrote:
> >
> > Add a helper for updating the SW_COLLAPSE bit during initialisation and
> > state updates.
> >
> 
> 
> > Note that the update during initialisation was relying on the
> > SW_COLLAPSE bit not having been set earlier rather than passing in zero
> > explicitly to clear the collapse vote.
> 
> I think this part deserves a separate commit with proper Fixes: tag.

No, it's not a bug. The value passed in is explicitly set a bit higher
up in the same function so that the SW_COLLAPSE bit is (currently) never
set.

It mostly just looks weird and probably wasn't intentional.

> > @@ -425,8 +437,7 @@ static int gdsc_init(struct gdsc *sc)
> >                  * If a Votable GDSC is ON, make sure we have a Vote.
> >                  */
> >                 if (sc->flags & VOTABLE) {
> > -                       ret = regmap_update_bits(sc->regmap, sc->gdscr,
> > -                                                SW_COLLAPSE_MASK, val);
> > +                       ret = gdsc_update_collapse_bit(sc, false);
> >                         if (ret)
> >                                 return ret;
> >                 }

Johan