writeCommand() had no way to send a non-zero ARG1, since it always
hardcoded ARG1=0x00 before the caller's payload. Every command whose real
ARG1 needed to carry a flag (STCACK, INTACK, SERTYPE, DIGRAD/EVENT ack) or
whose payload needed to start at ARG1 instead of ARG2 was silently broken:
- seekFm(): SEEKUP/WRAP never reached the chip (always ARG2=0x00), so
hardware seek always searched down/no-wrap; masked by the existing
100 kHz software-step fallback in Si4684Tuner.
- startDabService()/stopDabService(): SERVICE_ID/COMPONENT_ID shifted one
byte right of their real ARG4-11 positions, with SERTYPE landing where
the spec requires a fixed 0x00.
- readDabServiceData(): same shift, plus STATUS_ONLY was bit3 (0x08)
instead of the correct bit4 (0x10).
- clearFmStc(), readFmRsq(), readFmRds(), fetchDabServiceList(),
readDabDigRadStatus(), readDabEventStatus(): these AN649 commands have
only ARG1 and no ARG2 at all, so the old two-argument writeCommand()
could never carry their ack/status flags — clearFmStc()'s STCACK never
fired in this driver's history (masked by FM_TUNE_FREQ/FM_SEEK_START
auto-clearing STC per their own spec).
writeCommand() gains a fourth parameter, arg1 (default 0x00, preserving
every already-correct call site); each caller above now passes its flag
through arg1 instead of the payload array.
Confirmed live: first locked:true and first genuine hardware seek (not
software-fallback) in this driver's history — 87.5 -> 98.3 MHz, RSSI +12
dBuV, SNR +14 dB.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0178rASQ6ZETPMUamvpoR2KR
micheleandClaude Sonnet 5
f5fe92f93e