SyncWord Error causes self-inflicted SPI conflict and prevents concentrator initialization #213
Description
Self-inflicted SPI conflict due to SyncWord errors prevents concentrator initialization
Description
LoRa Basics Station sometimes fails to start the concentrator due to a self inflicted SPI conflict triggered by initial syncword errors.
Observed behavior
-
RX buffer receives repeated garbage bytes (
0x5) and fails to detect a valid syncword:no syncword found, discard rx_buffer -
The concentrator never starts:
Note: LoRa concentrator was not started... -
Station reports SPI device in use:
[any:CRIT] Radio device '/dev/spidev0.0' in use by process: <PID> -
Station attempts to kill the process using SPI, but it is actually its own PID, leading to a repeated self termination loop.
Impact
- Concentrator never initializes.
- SPI remains locked.
- Connection cannot be re-established.
Theorical Root cause
- Initial syncword errors leave the SPI file descriptor open.
- Station logic assumes any SPI in-use belongs to another process and issues a kill attempt.
- No distinction is made between self-owned and external SPI usage.