Symptom: Driver probe succeeds but data transfer fails. Register reads return expected ID. Interrupt never fires.
Verify IRQ number in device tree matches hardware connection.
Check IRQ type: level vs edge — driver must match.
Read interrupt status register — is the condition actually set?
Check how the selected source deasserts: W1C, read-to-clear, draining a FIFO or removing another condition. A level source does not universally require a register clear.
Verify clock is running to the peripheral (not gated).
Driver timeout without checking IRQ type and clear sequence.
DMA underrun/overrun from wrong watermark settings.
Accessing peripheral in power-gated domain.