From 114093ee0e8fd34ca7d7434e8cb8523bd6e1ba9d Mon Sep 17 00:00:00 2001 From: Fedor Kallay Date: Sat, 15 Aug 2026 02:13:11 +0200 Subject: [PATCH] fix(lr2021): setTxPower() could leave the receiver down until reboot RadioLibWrapper::setTxPower() called setOutputPower() and nothing else. On LR2021 that writes the PA config and TxParams, which are standby-only commands, and it never re-arms the receiver. This only affects LR2021 boards. recvRaw() has: #if defined(USE_LR2021) state = STATE_RX; // LR2021 stays in Rx after readData #else state = STATE_IDLE; // need another startReceive() #endif so on SX126x the next recvRaw() re-arms Rx anyway and the write is harmless, while on LR2021 startReceive() is never called again on its own. A 'set tx' issued while the radio was listening could therefore stop reception until the next reboot. Observed a few times on an LR2021 repeater; recovery required a power cycle. Dispatcher's stuck-radio check does not catch it: isInRecvMode() reports the wrapper's own `state` flag rather than the chip's actual mode, so it still believes the radio is in Rx, and it only raises ERR_EVENT_STARTRX_TIMEOUT without attempting recovery. Fix: on LR2021, drop to standby via idle() before writing the PA config and let checkRecv() re-arm Rx - the same pattern resetAGC() and applySideDetectorConfig() already use. Other radios are left untouched. Affects meshtracker_x1 and meshnology_w12 (both USE_LR2021). Tested on hardware with an LR2021 repeater: six consecutive 'set tx' changes (15/18/21/14/19/14), after which the radio kept receiving and forwarding traffic (rawrx/rxpkts increasing, no missed IRQs). Noise-floor sampling also kept updating, which only happens while state == STATE_RX. --- src/helpers/radiolib/RadioLibWrappers.cpp | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/src/helpers/radiolib/RadioLibWrappers.cpp b/src/helpers/radiolib/RadioLibWrappers.cpp index b9c095ac40..f404b62579 100644 --- a/src/helpers/radiolib/RadioLibWrappers.cpp +++ b/src/helpers/radiolib/RadioLibWrappers.cpp @@ -48,6 +48,17 @@ uint32_t RadioLibWrapper::getRngSeed() { } void RadioLibWrapper::setTxPower(int8_t dbm) { +#if defined(USE_LR2021) + // On LR2021, setOutputPower() writes the PA config and TxParams, which are + // standby-only commands. recvRaw() keeps state == STATE_RX after readData on + // this platform ("LR2021 stays in Rx"), so - unlike the SX126x path, which + // falls back to STATE_IDLE and re-arms on the next recvRaw() - nothing calls + // startReceive() again by itself. Writing the PA config while listening could + // therefore leave the receiver down until the next reboot. Drop to standby + // first and let checkRecv() re-arm Rx, as resetAGC() and + // applySideDetectorConfig() already do. + idle(); +#endif _radio->setOutputPower(dbm); }