Primary debug scenario

Symptom: Driver probe succeeds but data transfer fails. Register reads return expected ID. Interrupt never fires.

Triage steps

1. Verify IRQ number in device tree matches hardware connection.

2. Check IRQ type: level vs edge — driver must match.

3. Read interrupt status register — is the condition actually set?

4. Check interrupt clear sequence — level IRQ needs explicit clear.

5. Verify clock is running to the peripheral (not gated).

Common pitfalls

• Driver timeout without checking IRQ type and clear sequence.

• DMA underrun/overrun from wrong watermark settings.

• Accessing peripheral in power-gated domain.