Does db410c support suspend/resume functions?


#1

Hi All,

With Linux OE RPB 16.09, I press the power button on DragonBoard 410c, however, it does not enter suspend mode as I expected.
Instead, if I keep pressing the power button for 10 seconds, the system can shutdown.

So, is this a normal situation for db410c? Can it support suspend/resume function?

Thanks,
Daniel


Suspend to memory in Debian Linaro distro
#2

Hi Daniel,

Firstly, I have not tried this on Dragonboard 410c. But want below info can be helpful:

  • If we want power button to trigger “suspend” mode, we need provide driver for this input device and finally it will call kernel’s system suspend flow; So from your result, this is not supported on Dragonboard currently;
  • Press button 10 seconds and system shutdown, I think it’s highly related with PMIC hardware behavior. Usually the power button is connected with PMIC so if press button for long period it will trigger PMIC hardware shutdown or reset.
  • If you want try suspend flow, you could manually input command: echo mem > /sys/power/state.

Thanks,
Leo Yan


#3

Hi Leo,

Thanks for detailed explanation.
I try the command you mentioned on db410c, but get an error returned.


# echo mem > /sys/power/state
sh: echo: write error: Invalid argument

It looks like the system does not support suspend feature yet.

Thanks,
Daniel


#4

Hi Daniel,

I checked internally and currently db410c has not supported system suspend/resume. Sorry for this.

Thanks,
Leo Yan


#5

Hi Leo,

Thanks! That’s OK.
BTW, do you have plan to support this feature in the future?

Thanks,
Daniel


#6

Hi Daniel,

We have no plan to support suspend/resume on db410c at the moment.

There have one bug for power button so power button cannot be used for “shutdown” menu if press it single time. This bug should be fixed soon and power button will be used for “shutdown” flow.

Thanks,
Leo Yan


#7

Hi, any news about the support of supend / resume on the db410c?

thanks,
Sebastien.


#8

I would like to bring up the topic again.

The CortexA53 is the first CortexA processor with low power consumption. Especially this feature is highlighted from marketing. This makes the CortexA at first time suitable for projects where a CortexA8/9 doesn’t fit.

I think many users will need this feature. Straight with this board.

Leo, can you discuss this problem again internally. Even if there is currently no solution for this, a schedule for a possible implementation would help me very much.

At the moment I have not decided which board I will use. The favorite is the DART-SD410 or the Dragonboard DB410C. If the power management will not implemented in the future, I inevitably have to look for another platforms.

Thanks in advance
Hendrik