SyncWord Error causes self-inflicted SPI conflict and prevents concentrator initialization

[JoanSanfelipe]

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.