From ab061c8ddd9ea3d903ca171b0989ad8f557516bb Mon Sep 17 00:00:00 2001 From: Aleksander Morgado Date: Wed, 12 Jan 2022 15:41:55 +0100 Subject: [PATCH] modemmanager: remove 2s timeout before reporting cached events When ModemManager is started on boot we may end up with hotplug events reported directly to the daemon, plus some others already cached in the cache file before the daemon was started. If the cached events correspond to the same device that is still notifying ports directly, we may end up with a modem object created before the cached events have been emitted, so the modem may not handle all control/data ports it should. E.g.: - modem detected - hotplug event for wwan0 port, cached as MM not running - hotplug event for cdc-wdm0 port, cached as MM not running - hotplug event for ttyUSB0, cached as MM not running - MM starts - hotplug event for ttyUSB1, directly processed as MM is running - hotplug event for ttyUSB2, directly processed as MM is running - modem object created with ttyUSB1 and ttyUSB2 - 2s after MM starts, cached events for wwan0, cdc-wdm0 and ttyUSB0 happen, but are ignored because the modem object has already been created MM expects that ports of the same device are reported with less than 1500ms in between ports. In other words, if ports are reported more than 1500ms after the last reported port, they may get ignored. If we remove the 2s timeout, the report of the cached events will happen as soon as MM starts, which makes it much more likely to happen in the timeslot that MM expects for ports of the same device reported. The logic is still not perfect, and we may also need to increase that 1500ms timeout inside MM, but removing the 2s timeout right away here makes sense. This 2s timeout was introduced along with the new wrapper launcher for the daemon, it didn't exist before. Signed-off-by: Aleksander Morgado --- net/modemmanager/files/usr/sbin/ModemManager-wrapper | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/modemmanager/files/usr/sbin/ModemManager-wrapper b/net/modemmanager/files/usr/sbin/ModemManager-wrapper index f5fb6d1f2..4fd64227f 100644 --- a/net/modemmanager/files/usr/sbin/ModemManager-wrapper +++ b/net/modemmanager/files/usr/sbin/ModemManager-wrapper @@ -24,7 +24,7 @@ main() { /usr/sbin/ModemManager "$@" 1>/dev/null 2>/dev/null & CHILD="$!" - sleep 2 + mm_report_events_from_cache wait "$CHILD"