diydrones/ardupilot — pull request #1363 by badzz (2014-09-03 23:33:22+00:00)
Title: AP_HAL_PX4: Add semphore to io of UARTDriver

In order to avoid concurrent acces to the uartdriver, the IO are protected by a semaphore. Now, the lib will accept different thread accesing the uart. This is usefull for Frsky telemetry to be able to run in a separate thread.