[PATCH 0/2] ASoC: rockchip: i2s-tdm: register the PCM before the DAI

[Arun Iyengar via B4 Relay]

The Rockchip I2S-TDM driver registers its DAI component before the
dmaengine PCM component. A sound card that was registered earlier and
waits for the CPU DAI is bound by snd_soc_component_register() as soon
as the DAI component appears, which also satisfies the DAI link's
platform (it defaults to the CPU of_node), so the card binds without the
PCM component. Every open of the PCM then fails with -EINVAL from
snd_pcm_hw_constraints_complete(), silently. On RK3588 this happens to
the HDMI sound card whenever the HDMI codec probes before the I2S
controller. Patch 1 registers the PCM first, as rockchip_spdif already
does.

Patch 2 adds the missing regmap default for I2S_XFER, which otherwise
warns "using zero-initialized flat cache" on its first cached access.

The non-TDM rockchip_i2s driver has the same registration order; the
same change for it will follow once it is tested on a board that uses
that controller (the RK3588 board here only has I2S-TDM instances).

Tested on an Orange Pi 5 (RK3588S): with patch 1 the HDMI card has its
dma:fddf0000.i2s component (debugfs asoc/hdmi0), speaker-test on
plughw:CARD=hdmi0 plays, and "aplay -D hw:<hdmi>,0" no longer fails
with "Invalid argument" (traced before the fix to
snd_pcm_hw_constraint_mask returning -22 with no dmaengine component on
the runtime). With patch 2 the flat-cache warning for fddf0000.i2s is
gone and HDMI playback is unchanged.

This series was developed with Claude (Anthropic) as a coding assistant:
it wrote the code and the commit messages, and I reviewed and tested
every change as described above.

Signed-off-by: Arun Iyengar <aiyengar1990 at gmail.com>
---
Arun Iyengar (2):
      ASoC: rockchip: i2s-tdm: Register the PCM before the DAI
      ASoC: rockchip: i2s-tdm: add the reset value of XFER to the regmap defaults

 sound/soc/rockchip/rockchip_i2s_tdm.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)
---
base-commit: cde5523c75f1320a55ac1d55a717ccbb566557f0
change-id: 20261110-asoc-rockchip-i2s-tdm-d6a6f86e81a9

Best regards,
--  
Arun Iyengar <aiyengar1990 at gmail.com>