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Low Power mode in Android

Question asked by Amit Kulkarni on Aug 3, 2018
Latest reply on Aug 10, 2018 by Diego Adrian Cuevas

Hi,

 

We are using sabresd board running with Android  7.1.2

 

I want to enter into "Low power mode" using echo mem > /sys/power/state. But it fails. 

Below is the log: 

/ # echo mem > /sys/power/state
PM: suspend entry 1970-01-01 03:32:02.891862744 UTC
PM: Syncing filesystems ... mmc0: Switching to 3.3V signalling voltage failed
done.
Freezing user space processes ... (elapsed 0.002 seconds) done.
Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
Suspending console(s) (use no_console_suspend to debug)
sd 0:0:0:0: [sda] Synchronizing SCSI cache
sd 0:0:0:0: [sda] Stopping disk
mmc1: Switching to 3.3V signalling voltage failed
PM: suspend of devices complete after 83.607 msecs
PM: suspend devices took 0.090 seconds
PM: late suspend of devices complete after 1.593 msecs
PM: noirq resume of devices complete after 0.324 msecs
PM: noirq suspend of devices failed
PM: early resume of devices complete after 1.088 msecs
mmc1: Switching to 3.3V signalling voltage failed
mmc0: Switching to 3.3V signalling voltage failed
sd 0:0:0:0: [sda] Starting disk
PM: resume of devices complete after 85.463 msecs
PM: resume devices took 0.090 seconds
android_work: sent uevent USB_STATE=DISCONNECTED
Restarting tasks ... done.
mmc1: Switching to 3.3V signalling voltage failed
PM: suspend exit 1970-01-01 03:32:03.640829411 UTC
1|toradex_apalis6q:/ # android_work: sent uevent USB_STATE=CONNECTED
configfs-gadget gadget: high-speed config #1: b
android_work: sent uevent USB_STATE=CONFIGURED
mtp_open
ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata1.00: configured for UDMA/133
sda: detected capacity change from 0 to 16013942784

 

am i doing it in correct way ? Why does it fail ? How to enter to low power mode ? and also resume back ?

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