Re: [PATCH v2 2/2] arm64: dts: qcom: Add base qrb4210-rb2 board dts

[Bjorn Andersson]

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@xxxxxxxxxx>
> >> ---
> [...]
> 
> >> +	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