Date:   Fri, 12 Nov 2021 13:19:25 +0000
From:   Daniel Thompson <daniel.thompson@linaro.org>
To:     Marijn Suijten <marijn.suijten@somainline.org>,
        phone-devel@vger.kernel.org, Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Lee Jones <lee.jones@linaro.org>,
        Jingoo Han <jingoohan1@gmail.com>,
        ~postmarketos/upstreaming@lists.sr.ht,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@somainline.org>,
        Konrad Dybcio <konrad.dybcio@somainline.org>,
        Martin Botka <martin.botka@somainline.org>,
        Jami Kettunen <jami.kettunen@somainline.org>,
        Pavel Dubrova <pashadubrova@gmail.com>,
        Kiran Gunda <kgunda@codeaurora.org>,
        Bryan Wu <cooloney@gmail.com>, linux-arm-msm@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
        Courtney Cavin <courtney.cavin@sonymobile.com>
Subject: Re: [RESEND PATCH v2 04/13] backlight: qcom-wled: Fix off-by-one
 maximum with default num_strings
Message-ID: <20211112131925.fqallv3z73ehc6y3@maple.lan>
References: <20211112002706.453289-1-marijn.suijten@somainline.org>
 <20211112002706.453289-5-marijn.suijten@somainline.org>
 <20211112120839.i6g747vewg6bkyk7@maple.lan>
 <20211112123501.pz5e6g7gavlinung@SoMainline.org>
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On Fri, Nov 12, 2021 at 01:35:01PM +0100, Marijn Suijten wrote:
> On 2021-11-12 12:08:39, Daniel Thompson wrote:
> > On Fri, Nov 12, 2021 at 01:26:57AM +0100, Marijn Suijten wrote:
> > > +		if (string_len > 0) {
> > > +			dev_warn(dev, "qcom,num-strings and qcom,enabled-strings are ambiguous\n");
> > 
> > The warning should also be below the error message on the next if statement.
> 
> Agreed.
> 
> > This warning occurs even when there is no ambiguity.
> > 
> > This could be:
> > 
> > 	if (string_len > 0 && val != string_len)
> > 
> > Combined these changes allows us to give a much more helpful and assertive
> > warning message:
> > 
> > qcom,num-strings mis-matches and will partially override
> > qcom,enabled-strings (remove qcom,num-strings?)
> 
> I want to let the user know it's set regardless of whether they're
> equivalent; no need to set both.
> 
> How about:
> 
>     Only one of qcom,num-strings or qcom,enabled-strings should be set
> 
> That should be more descriptive?  Otherwise, let me know if you really
> want to allow users to (unnecessarily) set both - or if it can / should
> be caught in DT validation instead.

Yes. I can live with that text. Let's use that.

Maybe I wouldn't if there gazilions of existing DTs with both
properties but IIRC the number is likely to be small or zero
(although we couldn't be 100% sure which).


Daniel.