dmitrystu / libusb_stm32

Lightweight USB device Stack for STM32 microcontrollers
Apache License 2.0
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Avoid ModemManager blocking the virtual serial port #39

Closed nickray closed 5 years ago

nickray commented 5 years ago

With current udev, if ModemManager is running and CDC class device signals AT support, then access to /dev/ttyACMx is blocked for about 10 seconds until ModemManager gives up. This can be avoided by not signaling AT modem command support (see https://gitlab.freedesktop.org/mobile-broadband/ModemManager/issues/111 for discussion of same issue).

microwavesafe commented 5 years ago

This is good to know, I suffer from the same problem with NetworkManger in Linux. Previously I've disabled NetworkManager, this is a much better solution.

nickray commented 5 years ago

FYI, it's sufficient to disable ModemManger (not entire NetworkManager) in such cases (if the equivalent of this patch cannot be applied.) You probably don't need ModemManager, but you probably do need NetworkManager :)