Duncan,

took a look at the IT8772F data sheet (well, 8712, closest I could find: http://www.hardwaresecrets.com/datasheets/it8712f.pdf ) and it seems that there's no setting of the PCR1/2 registers that will force #PSON high when AC power is applied - it's always conditional on the previous system power state.

I'd be happy for someone else to take a look and tell me I'm misreading though :)

cheers,
Matt

On 3/26/2015 5:21 PM, Matt DeVillier wrote:
On 3/26/2015 9:49 AM, Duncan Laurie wrote:
On Wed, Mar 25, 2015 at 11:35 PM, Matt DeVillier <matt.devillier@gmail.com> wrote:
Greetings all!

I was wondering if it's possible to have Panther (Asus ChromeBox - Haswell/Lynxpoint) power on when AC power connected regardless of the previous power state.  Currently, the box will power on if AC power is lost and the device was powered on, but not if powered off.  I have a use case where it would be convenient to be able to power on the boxes by toggling AC power (eg, the boxes are not within physical reach).  I modified the CMOS default setting for 'power_on_after_fail' to be enabled and verified its status with nvramtool.  I also tried modifying lpc.c/smihandler.c in the southbridge code to force MAINBOARD_POWER_ON (rather than MAINBOARD_POWER_KEEP) in all cases, to no avail.

Am I approaching this from the wrong angle, or is it perhaps not possible with these boxes?



This might be due to the SuperIO instead of the Southbridge.  Panther does call it8772f_ac_resume_southbridge() which *should* be making the southbridge the one responsible for the power behavior when AC is applied, but as a first test you could try removing that call to see if the default SuperIO behavior is closer to what you want.

Hi Duncan, I tried removing the call as suggested, but it didn't change the behavior at all.  Any thoughts as to where to look next?

thanks!
-Matt


-duncan