Quectel EC25A ACPI wakeup after 15 seconds

[Dan Williams]

On Wed, 2018-10-10 at 14:32 -0700, Christopher McKenzie wrote:
> Hi,
> 
> I have a number of Quectel EC25AFAR05A04M4G hooked up to some J1900 
> celerons (board info 
> https://solutionsdirectory.intel.com/it/node/70126).  When I issue 
> acpitool -s (S3), it will resume in 15 seconds. I've narrowed this
> down 
> to the EC25 as it stays asleep when the device is removed.
> 
> I've tried a number of things, such as trying to modify the power
> level 
> (as in turning the usb port "off") or the wakeup node in the mapped 
> device entry. I've tried toggling the acpi wakeup events to
> disabled, 
> overwriting the the acpid events to be disabled, disable acpi
> entirely 
> and use solely systemd's methods, this all fails. I've looked around
> the 
> BIOS but found no ways to modify this and it seems to do the same
> thing 
> in Windows although the ACPI event that gets fired is listed as 
> unknown.  I've also tried disabling all the modem features, 
> disconnecting from the APN, and tearing down the network. None of
> these 
> things seem to alleviate the problem.
> 
> Has anyone run into this before and if so, do you know of any
> solutions? 

This could be a kernel driver issue; some QMI devices need DTR toggled
to wake up.  But I see that the EC25 already has this quirk in the
kernel driver, at least as of the 4.8 kernel.  What kernel version do
you have?

But I also see that GobiNet pokes the DTR on resume too, and I don't
see that functionality in qmi_wwan or usbnet, though I might be missing
it.

Maybe try calling:

		qmi_wwan_change_dtr(dev, true);

in qmi_wwan_resume() before usbnet_resume().

Dan