Re: [PATCH v7] ASoC: tas2783-sdw: add firmware download status check

[Lee Mann <leepaulmann@gmail.com>]

Hi Baojun,

This patch, now in v7.4-rc1 as f42fbd560cd8, drops the stereo split
from tas2783_sdw_hw_params() (v5 changelog: "stereo configuration
should be handled by the DisCo table"). On the ASUS ProArt PX13
(HN7306EA, AMD ACP, 2x TAS2783 on SoundWire link 1) that table is
never applied, so the split was what gave stereo there.

The ASUS ACPI declares the SDCA function type without a DisCo constant.
Both amps log "function type only supported as DisCo constant",
find_sdca_function() bails out and the per-amp init table is never
written. ClusterIndex (SDW_SDCA_CTL(1, PPU21, 0x10, 0)) then stays at
0x01 from tas2783_init_seq on both amps.

Tested on 7.3.1 by ear with speaker-test -c2 -t wav, by swapping only
snd-soc-tas2783-sdw:

  tas2783-sdw.c from v7.3 (+ a local volume-restore patch, no
  channel changes)             : Front Left left, Front Right right
  tas2783-sdw.c from v7.4-rc1  : Front Left from the left speaker,
                                 Front Right not heard at all, right
                                 speaker silent

The v7.4-rc1 driver probes cleanly (no tas2783 errors in the kernel
log, both amps Attached), so with this patch the PX13's right speaker
no longer works on a stock v7.4 kernel.

I agree the split is wrong where the DisCo init table is applied. I
saw that myself with the SDCA fallback from SOF PR #5904 (which makes
the PX13 table apply: 0x01 on amp 0x8, 0x04 on amp 0xb): with the
split, amp 0xb went silent; with the full mask, stereo. So the two
cases need different handling. Two options I can see:

 - keep the split only when no SmartAmp function data was parsed
   (sa_func_data absent), or
 - land a fallback that lets the ASUS table be parsed (PR #5904 does
   this for mfg 0x0102) before 7.4 final.

I'm happy to test either on the PX13.

#regzbot introduced: f42fbd560cd8
#regzbot title: ASoC: tas2783-sdw: right channel lost on ASUS ProArt PX13 after stereo split removal

Thanks,
Lee Mann