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Subject: Re: [PATCH v4 2/3] clk: qcom: clk-rcg2: add support for rcg2 freq multi ops
From:   Stephen Boyd <sboyd@kernel.org>
Cc:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Michael Turquette <mturquette@baylibre.com>,
        linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org,
        linux-kernel@vger.kernel.org
To:     Christian Marangi <ansuelsmth@gmail.com>,
        Konrad Dybcio <konrad.dybcio@linaro.org>
Date:   Wed, 14 Jun 2023 17:28:08 -0700
User-Agent: alot/0.10
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Quoting Christian Marangi (2023-05-29 05:34:57)
> On Mon, May 29, 2023 at 02:12:23PM +0200, Konrad Dybcio wrote:
> > On 28.05.2023 14:37, Christian Marangi wrote:
> > > On Sat, May 27, 2023 at 06:11:16PM +0200, Konrad Dybcio wrote:
> > >> On 27.04.2023 17:07, Christian Marangi wrote:
> > >>> +  * Force the first conf if we can't find a correct config.
> > >>> +  */
> > >>> + if (unlikely(i =3D=3D f->num_confs))
> > >>> +         best_conf =3D f->confs;
> > >> Is that a supported scenario or would it be a device driver / clock
> > >> driver error?
> > >>
> > >=20
> > > It's to handle case for the 2 continue in the loop and arriving in a
> > > situation where best_conf was never set?
> > >=20
> > > Should we return a warning and an ERR_PTR? Idea was to provide a best
> > > effort selection.
> > Hm.. I'm not sure what's the expected behavior here.. Stephen?
> >=20
>=20
> I have this implementation rady, if you want I can send this revision
> and discuss that in v5 directly. It's WARN and returning -EINVAL.

I'd only have a WARN if you never expect to hit that case. Otherwise, it
should return -EINVAL and not warn. At a quick glance it sounds like
some sort of rounding policy, so just make sure the
round_rate/determine_rate implementation agrees with what set_rate()
will do and it should be good.