pine64-pinephone: modem-control ➡ eg25-manager

[tomfitzhenry]

Fixes #348 and #463.

Background: There are ways to control the modem's lifecycle on Pinephone: eg25-manager and Megi's modem-power driver. Other Linux distros have settled on using eg25-manager.

This PR moves Mobile NixOS from modem-power to eg25-manager.

This has a few benefits:

• Aligning with other Linux distos will result in less maintenance/issues for us.
  • Postmarket OS use the patch: https://gitlab.com/postmarketOS/pmaports/-/blob/0ee32f2558da6acdf7a78d7acb9e138b3f3a17cf/device/main/linux-postmarketos-allwinner/0007-dts-pinephone-drop-modem-power-node.patch
  • Arch Linux use the patch: https://github.com/dreemurrs-embedded/Pine64-Arch/blob/master/PKGBUILDS/pine64/linux-megi/dts-pinephone-drop-modem-power-node.patch
  • Mobian have their Linux fork which has no modem-power. https://gitlab.com/mobian1/devices/sunxi64-linux/-/tree/mobian-5.16/debian/patches
• eg25-manager binds to ModemManager health (a better signal for modem health)
• Safer integration with fwupd: pine64-pinephone: modem-control.service conflicts with fwupd modem firmware writing #463

Notes:

• I'm packaging eg25-manager 0.4.2 rather than eg25-manager 0.4.3 because 0.4.3 relies on too recent a Meson version.
• I initially packaged eg25-manager for nixpkgs ( networking/eg25-manager: init at 0.3.0 nixpkgs#129229 ), but it was suggested that mobile-nixos was a better for this to live.

[tomfitzhenry]

I've documented modem managers and how to test them (e.g. "can receive a call when asleep") in https://wiki.pine64.org/wiki/PineModems#Modem_management . I will update this PR once I've completed those tests.

[tomfitzhenry]

I've performed the tests listed on https://wiki.pine64.org/wiki/PineModems#Modem_management :

• Modem is recognized by ModemManager on boot. eg25-manager.log
• Can make a call
• Can receive a call
• Can receive a call when asleep: systemctl suspend

[zhaofengli]

Tested working as well:

• Modem is recognized by ModemManager on boot. eg25-manager.log
• Can make a call
• Can receive a call
• Can receive a call when asleep: systemctl suspend

I have tested this to be working on my Pinephone with:

systemd.packages = [
  pkgs.eg25-manager
];

systemd.targets.multi-user.wants = [ "eg25-manager.service" ];

services.dbus.packages = [
  pkgs.eg25-manager
];

Should this replace what was previously in modem.nix? The modem should work out of the box without manual configuration.

[tomfitzhenry]

Should this replace what was previously in modem.nix? The modem should work out of the box without manual configuration.

Good idea. I've updated this PR to include that config.

[tomfitzhenry]

I've moved this PR to back to draft, so I can test the changes discussed in #464 (comment).

[tomfitzhenry]

I've moved this PR to back to draft, so I can test the changes discussed in #464 (comment).

Done. The modem still starts successfully on boot, with the most recent change of keeping mobile.quirks.u-boot.additionalCommands.

[samueldr]

The modem options needs to be trivial to enable/disable.

Lists in the NixOS modules system won't allow removing items added to them.

Couple that with the fact that eg25-manager dependencies don't cross-compile, this makes for an awkward situation when trying to build examples/hello, which should always build successfully.

Furthermore, with the Pinephone Pro, I believe this should be broken out in a more discrete option set that can be used on any device.

So I guess the option should default = false, since otherwise it would be enabled on irrelevant platforms. Then it should be mkDefault'ed to true in the pinephone [and pro] configs. Finally, cross-workarounds could warn and force disable it [though the warning would always be shown even on platforms not relying on eg25-manager... hmmmm].

Thoughts?

[IreneKnapp]

I'm doing related work, I'm just replying to this thread so I'll see future remarks on it. We should sync up over on Matrix.

[samueldr]

Adding some more notes/clues, I think adding them as quirks under the mobile.quirks.quectel.eg25-modem, gated behind an enable option would be the way to go.

I'm assuming this would also be the same exact implementation for the Pinephone Pro, maybe @wentam can confirm?

If it's not, maybe it's something that's not specific to the "host" hardware (the phone), but something specific to the "integration" of the software (kernel, services), and in that case differentiated with an option as needed.

[wentam]

Adding some more notes/clues, I think adding them as quirks under the mobile.quirks.quectel.eg25-modem, gated behind an enable option would be the way to go.

I'm assuming this would also be the same exact implementation for the Pinephone Pro, maybe @wentam can confirm?

The setup to run eg25-manager on pinephone pro should be exactly the same as pinephone, yes.

I've been running the following in my configuration.nix on PPP (with a locally packaged eg25-manager to get a newer version):

  # eg25-manager
  systemd.packages = [ eg25-manager ];
  systemd.targets.multi-user.wants = [ "eg25-manager.service" ];
  services.dbus.packages = [ eg25-manager ];

+1 for wrapping it up in a module and providing a simple enable flag.

[tomfitzhenry]

[Going through my Github PRs and closing stale ones.]

My progress stalled on this a while ago. I'll close to make it clear to other contributors that I don't intend to get back to this.