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IMX6ULL mem/idle power usage

Question asked by Michiel TJampens on Jun 15, 2020
Latest reply on Jun 22, 2020 by Michiel TJampens

I've used the latest BSP to generate a bootloader and kernel, then based on the DTS from the evk and the default one from the manufacturer of the carrier board (attached) I made a DTS (attached) to suit my needs which are:

  • one ethernet
  • as many as possible UART
  • two i²c

I think I disabled pretty much everything else. But power consumption is nowhere as low as i hoped...

  • idle (eth0 'okay' but no cable attached, usb eth gadget) 953mW
  • idle but eth0 and usb0 down  750mW
  • standby  580mW (and 'mem' doesn't seem to make a noticable difference)

 

When using the default dtb from the carrier manufacturer (single uart,no i2c, both eth available)

  • idle (both eth okay but no cable attached, usb eth gadget, single uart ok)  is 815mW
  • idle both eth down, usb0 down 335mW

 

According to the power consumption app note i should use 

echo 1 > /sys/bus/platform/drivers/imx_busfreq/soc\:busfreq/enable

But this doesn't make a difference in the above scenario's.

 

So before i try to dig even deeper:

  • is it normal that UART's make such a big difference to the 'idle' state?
  • what would be the reason standby and mem don't make a difference?
  • is there a document/table somewhere that shows things like 'if you enable this module, then this will be the result of on the overall current draw?

I've attached imx6ull-das which is the dtb for the uarts etc and imx6ull-seeed with is the default i'm referring to.

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