Three correctness fixes for the SX127x radio adapter on top of
Rastislav's initial sx1276 + patch commits:
1. _loramac_node flag (LoRaRadioBase + SX127xRadio):
Guard the direction-only fast path in configureTx()/configureRx()
so loramac-node always calls both Radio.SetTxConfig() and
Radio.SetRxConfig(). Skipping either leaves TxTimeout=0 in the
library, causing an immediate TX timeout callback, which prevents
the _tx_signal from ever being raised and blocks the TX wait thread
for TX_TIMEOUT_MS (5 s) — a 5-second RX blackout per transmission.
This was the root cause of "boots but no RX".
2. SX127xRadio::resetAGC() override:
The base-class resetAGC() calls startReceive() after hwResetAGC().
During async RX the loramac-node modem mutex is STATE_BUSY, so
lora_recv_async() returns -EBUSY, which sets _in_recv_mode = 0 and
corrupts the receive state machine. Override skips the call
entirely — the loramac-node driver self-manages AGC.
3. BW 62.5 kHz support in loramac-node/sx1276.c + patch:
Rastislav's 0004-lora-sx127x-62k5-bandwidth.patch adds BW_62_KHZ
support to sx12xx_common.c (Zephyr side) but not to the loramac-
node library itself. Without this fix bandwidth index 3 hits the
"while(1)" fatal guard in SX1276SetRxConfig/SX1276SetTxConfig.
This commit patches sx1276.c directly and adds
patches/modules/loramac-node/0001-sx1276-bw62k5.patch so the fix
survives west update. CMakeLists.txt is extended to apply module
patches via the existing zephcore_apply_patches() mechanism.
liquidraver