[PATCH v2 2/2] arm64: dts: rockchip: Add Radxa E54C
Shawn Lin
shawn.lin at rock-chips.com
Sun Oct 11 23:55:03 PDT 2026
Hi Chukun
在 2026/10/12 星期一 14:40, Chukun Pan 写道:
> Hi,
>
>> I was checking all PCIe part of rockchip dts files and wondered why it's
>> marked as an always-on regulator. But if it's actually not, it'd be
>> better to improve it later. That would make reset rootport mechanism
>> work better.
>
> Please refer to page 21 of the schematic[1]. The 3V3_PCIE regulator
> is enabled by the PMIC and cannot be controlled by the kernel. So I
> think it's correct to mark it as always-on.
>
> [1] https://dl.radxa.com/e/e54c/hw/radxa_e54c_v1.2_schematic.pdf
>
Thank you for providing the schematic. It does appear to be in an
uncontrolled state. Theoretically, PCIe control timing requires a
controllable power supply. The current design may cause trouble
enumerating certain devices due to always-on power. Unfortunately, this
board already has always-on power, so let's just leave it as is.
> Thanks,
> Chukun
>
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