Modem on Droid 4 (mdm6600) in recent mainline

From: Pavel Machek
Date: Wed Jul 29 2020 - 18:08:11 EST


Hi!

There's something very wrong with /dev/ttyUSB4 in recent kernels:
unsolicited incoming data from the modem are getting lost; I believe
it means also SMS notifications, but it is very easy to reproduce with
incoming call notifications.

They just don't come.

But if you keep pasting "AT" into minicom, they actually do.

Of course... that means that trying to debug ofono is ... "interesting".

I tried playing with
/sys/bus/platform/drivers/phy-mapphone-mdm6600/usb-phy\@1/power/control
files and timeouts, but could not get it to work.

Any idea what could be wrong there?

Is there easy way to disable power management for testing?

Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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