ls1027 reduce static power consumption

mikelooijmans — Mon, 12 Aug 2024 10:05:19 GMT

Our LS1027A board is using way more static power than we anticipated. The LS1027A is using about 4W of static power when idle.

The CPU frequency is lowered to 300MHz and Linux is entering the low-power states, as we can see in /sys/devices/cpu...

Changing the frequency (while idle) to 1500 MHz doesn't have much effect on the power consumption (about 30mW or so), which, to me, confirms that the low-power WFI states are doing their work.

We have no clue where the LS1027A is spending all this static power.

We're not using the networking components. We disabled everything we're not using in the device-tree.

I also tried disabling more of the network components by setting "ENETC_RCW=0" in the RCW, but saw no noticable effect.

Putting the CPU in suspend-to-RAM mode reduced the power a bit, but still about 3W remains, which is excessively large (compared to other systems I've worked with, where the CPU would go far below 1W while suspended).

What's using all that static power? And how can we diagnose and reduce it?

Re: ls1027 reduce static power consumption

mikelooijmans — Fri, 23 Aug 2024 05:59:18 GMT

A significant amount is used by the PCIe interfaces - we're using 2x 2 lane Gen3.

It seems that the LS1027 doesn't support PCI link power states, is that correct or is there something we should do to enable that?

Re: ls1027 reduce static power consumption

June_Lu — Tue, 27 Aug 2024 01:39:45 GMT

A significant amount is used by the PCIe interfaces - we're using 2x 2 lane Gen3.

How do you test and ananyse the PCIe interfaces power consumption?

Thanks

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ls1027 reduce static power consumption

Re: ls1027 reduce static power consumption

Re: ls1027 reduce static power consumption