Fix STM32 UART: Add separate TX waker and only clear idle flag in RingBufferedUartRx #3930
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lulf
approved these changes
Mar 6, 2025
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This resolves an issue whereby one is unable to use a
UartTxand aRingBufferedUartRxin parallel in separate tasks.Firstly, it changes
clear_idle_flagto ONLY clear the idle flag as the name suggests it should. Currently, it clears ALL set flags including TC which is checked byUartTx::flush. If the TX and RX are being used in parallel, it is possible for the RX to clear the TC flag before the TX can check it, which causesUartTx::flushto hang forever.Secondly, it adds a separate
tx_waker, otherwise when TX and RX are used in parallel they contend for the currently lonerx_wakerand can overwrite each others wakers, causing hanging.