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Date:   Mon, 10 Apr 2023 10:12:15 -0700
From:   Bjorn Andersson <andersson@kernel.org>
To:     Konrad Dybcio <konrad.dybcio@linaro.org>
Cc:     Bhupesh Sharma <bhupesh.sharma@linaro.org>,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        agross@kernel.org, linux-kernel@vger.kernel.org,
        bhupesh.linux@gmail.com, robh+dt@kernel.org,
        krzysztof.kozlowski@linaro.org
Subject: Re: [PATCH v2 2/2] arm64: dts: qcom: Add base qrb4210-rb2 board dts
Message-ID: <20230410171215.t65hic7uveeayfja@ripper>
References: <20230315210145.2221116-1-bhupesh.sharma@linaro.org>
 <20230315210145.2221116-3-bhupesh.sharma@linaro.org>
 <20230315223604.ofy7vm3bpccf5aul@ripper>
 <79731f2a-83e5-1e35-d450-456492cc5df2@linaro.org>
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On Thu, Mar 16, 2023 at 12:52:10AM +0100, Konrad Dybcio wrote:
> 
> 
> On 15.03.2023 23:36, Bjorn Andersson wrote:
> > On Thu, Mar 16, 2023 at 02:31:45AM +0530, Bhupesh Sharma wrote:
> >> Add DTS for Qualcomm qrb4210-rb2 board which uses SM4250 SoC.
> >>
> >> This adds debug uart, emmc, uSD and tlmm support along with
> >> regulators found on this board.
> >>
> >> Also defines the 'xo_board' and 'sleep_clk' frequencies for
> >> this board.
> >>
> >> Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
> >> ---
> [...]
> 
> >> +	vmmc-supply = <&vreg_l24a_2p96>;
> > 
> > Is there any reason why this platform doesn't require the vmmc supply to
> > be driven to HPM? This has traditionally been coming back biting us
> > through some stability issues later.
> Do we even support HPM/LPM on SMD RPM?
> 

We support specifying the load, which will trickle down to have the
HPM/LPM effect. You can find an example of this, with motivation in [1].

PS. While looking for an example I found [2]. regulator-system-load
doesn't do anything unless regulator-allow-set-load is defined...

[1] e38161bd325e ("arm64: dts: apq8096-db820c: Increase load on l21 for SDCARD")
[2] 1d99fee382a6 ("arm64: dts: qcom: sdm845-tama: Add regulator-system-load to l14a/l28a")

Regards,
Bjorn