From 235eff02ac4c6bac53650697a54094390ea7f444 Mon Sep 17 00:00:00 2001
From: Dylan Van Assche <me@dylanvanassche.be>
Date: Fri, 12 Feb 2021 19:32:18 +0100
Subject: [PATCH] udev: add udev rule to configure modem USB

Quectel advises to configure the USB autosuspend feature as:
- power/control: auto
- power/autosuspend_delay_ms: 3000

Futhermore, the following settings are also needed:
- power/wakeup: enabled
- power/persist: 0
- avoid_reset_quirk: 1
---
 udev/80-modem-eg25.rules | 1 +
 udev/configure-usb-modem | 8 ++++++++
 2 files changed, 9 insertions(+)
 create mode 100644 udev/80-modem-eg25.rules
 create mode 100644 udev/configure-usb-modem

diff --git a/udev/80-modem-eg25.rules b/udev/80-modem-eg25.rules
new file mode 100644
index 0000000..163ec57
--- /dev/null
+++ b/udev/80-modem-eg25.rules
@@ -0,0 +1 @@
+ACTION=="add", SUBSYSTEM=="tty", ATTRS{idVendor}=="2c7c", ATTRS{idProduct}=="0125", ENV{.LOCAL_ifNum}=="02", RUN+="/usr/bin/configure-modem-usb"
diff --git a/udev/configure-usb-modem b/udev/configure-usb-modem
new file mode 100644
index 0000000..97468fc
--- /dev/null
+++ b/udev/configure-usb-modem
@@ -0,0 +1,8 @@
+#!/bin/sh
+
+# Avoid USB resets
+echo "auto" > /sys/bus/usb/devices/3-1/power/control
+echo "3000" > /sys/bus/usb/devices/3-1/power/autosuspend_delay_ms
+echo "enabled" > /sys/bus/usb/devices/3-1/power/wakeup
+echo "1" > /sys/bus/usb/devices/3-1/avoid_reset_quirk
+echo "0" > /sys/bus/usb/devices/3-1/power/persist