I am running an Open Embedded image that I built late last week:
console-image
Here is what I did and what happened:
root@beagleboard:~# echo -n mem > /sys/power/state
PM: Syncing filesystems ... done.
Freezing user space processes ... (elapsed 0.00 seconds) done.
Freezing remaining freezable tasks ... (elapsed 0.00 seconds) done.
Suspending console(s)
TWL4030 Audio Codec suspend
TWL4030 Audio Codec dapm event
Class driver suspend failed for cpu0
PM: Some devices failed to power down
clock: clksel_round_rate_div: dpll4_m4_ck target_rate 108000000
clock: new_div = 4, new_rate = 108000000
TWL4030 Audio Codec resume
TWL4030 Audio Codec dapm event
TWL4030 Audio Codec dapm event
Restarting tasks ... done.
root@beagleboard:~#
The really odd part is that the board is drawing 240mA before the
suspend attempt, but right about the time the clocks are being
reconfigured, the current consumption jumps to 800+mA briefly and then
settles to around 710mA. This as measured with a Fluke 189 sitting in
line between my bench power supply and the board. My bench supply is
set at 5V and a current limit of 900mA.
I don't mind debugging the suspend issue, but the problem is that the
high current draw is a concern. I am afraid that it is stressing
something on the board. Thankfully I was looking at the current
consumption the first time I did this, and I was quickly able to
shutdown the power when the current draw jumped. I was actually
looking to see how low the current consumption would go and not how
high it could get...
Has anyone else tried to suspend to memory, and if you did, what
happened?
The power management settings in the build configuration are: