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Date:   Mon, 23 Oct 2023 16:11:14 -0700
From:   Bjorn Andersson <quic_bjorande@quicinc.com>
To:     Mark Brown <broonie@kernel.org>
CC:     Stephan Gerhold <stephan.gerhold@kernkonzept.com>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        <linux-kernel@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>,
        Stephan Gerhold <stephan@gerhold.net>
Subject: Re: [PATCH RFC 1/2] regulator: core: Disable unused regulators with
 unknown status
Message-ID: <20231023231114.GO3553829@hu-bjorande-lv.qualcomm.com>
References: <20231004-reg-smd-unused-v1-0-5d682493d555@kernkonzept.com>
 <20231004-reg-smd-unused-v1-1-5d682493d555@kernkonzept.com>
 <80307316-f55e-4540-9c5f-655844c3b3f4@sirena.org.uk>
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On Mon, Oct 23, 2023 at 01:09:11PM +0100, Mark Brown wrote:
> On Wed, Oct 04, 2023 at 04:17:17PM +0200, Stephan Gerhold wrote:
> 
> > Instead of -EINVAL we could also use a different return code to indicate
> > the initial status is unknown. Or maybe there is some other option that
> > would be easier? This is working for me but I'm sending it as RFC to get
> > more feedback. :)
> 
> The more normal thing here would be -EBUSY I think - -EINVAL kind of
> indicates that the operation will never work while in reality it could
> possibly work in future.  Though for the RPMH it's not really the case
> that it ever supports readback, what it does is have it's own reference
> counting in the driver.  Rather than doing this we should probably have
> logic in the core which sees that the driver has a write operation but
> no read operation and implements appropriate behaviour.

I like the suggestion to not implement is_enabled, and handle that in
the core instead, for all three generations of our rpm-based regulators.

Regards,
Bjorn