PinePhone: modem takes 30s to power off

We are sleeping 30s on power off to wait for the modem:

https://gitlab.postmarketos.org/postmarketos/pmaports/-/blob/1039f705fb7199d620368f7374db2ef537d67dd8/device/community/device-pine64-pinephone/eg25.initd#L36

The datasheet says to wait 29.5s, according to @icenowy in !620 (comment 214688632).

Still, it seems unintuitive that we need to wait that long. Maybe we can implement @z3ntu's suggestion instead from !620 (comment 214566457):

I know that the modem prints a message like "powered off" when it's safe to power it off, so that would be useful to check and exit directly there.

(Furthermore I'm wondering... should we sleep at all? If the user takes out the battery and reboots, the modem does not have time to shutdown either.)

changed milestone to %[device] PinePhone support

added discussion help wanted labels

added category::device label

There are reports of modem's firmware corruption, most likely because he took the battery out without waiting for the shutdown too many times.

@z3ntu 's suggestion is a good idea.

By jane400 on 2020-09-02T10:52:52

https://megous.com/git/linux/commit/?h=modem-5.8&id=9e26fe7200672c64256652b916319873fd602ebf

• • Power up/power down:
• • • may take a lot of time (eg. ~13-22s powerup, >22s powerdown)
• • • happens on a private workqueue under a lock
• • • may happen from shutdown hook
• • • prevents suspend when powerup/powerdown is in progress
• • • is serialized and there's no abort of in-progress operations
• • • for specific power sequence see comments in the section for each
• • supported modem variant
• • • the driver monitors the power status of the modem (optionally)
• • and tries to complete the powerdown initiated via AT command
• • • the driver tries to detect when the modem is killswitched off
• • and updates the driver status to reflect that

So we could see a 8 second improvment at max.

By jane400 on 2020-09-07T19:45:56

!1533 (closed) We could use the the modem power control driver in megi's kernel.

By jane400 on 2020-09-07T19:47:35

I have received my pinephone yesterday. I am not able to turn off my phone, PinePhone postmarketOS CE edition. Also restart does not work.

Update: The phone only powers off if I try to do this after some minutes when it's turned on. I used the phone yesterday a few hours. And then tried to turn it off, it was not possible. I will do some more different use case tests and update this post.

By Ghost User on 2020-09-17T11:06:48

@incyi: thanks for the report! when you figure out more, please open a new issue and link to it. This one is about a known sleep before powering off, related to the modem. What you are describing sounds like poweroff/reboot unexpectedly not working.

By Oliver Smith on 2020-09-17T11:06:58

I've also experienced this, I created a formal issue at #790 (closed).

By Newbyte on 2020-09-17T16:44:56

mentioned in issue #790 (closed)

By Newbyte on 2020-09-17T16:43:28

mentioned in merge request !1614 (closed)

By Newbyte on 2020-10-09T12:09:19

Fixed by !1614 (closed).

By Oliver Smith on 2020-10-29T20:02:28

closed