[PATCH v4 0/2] ASoC: codecs: nau8360: Fix DSP routing and deadlock issues

[Neo Chang <YLCHANG2@nuvoton.com>]

This patch series addresses two issues in the nau8360 codec driver
regarding the DAC mux control:

1. An invalid hardware routing state that occurs when the DSP firmware
   fails to load but the userspace attempts to switch to the DSP path.

2. A pre-existing AB-BA deadlock triggered during concurrent stream
   startups or ALSA mixer updates.

---
Changes in v4:
- Patch 1/2: Changed the return value to -EBUSY instead of 0 to properly
  reject the invalid request and prevent ALSA state desync.
- Patch 1/2: Used dev_warn_ratelimited() instead of dev_warn().
- Patch 2/2: Added a fix for the AB-BA deadlock in nau8360_dac_mux_put_enum().
  (Reported by Sashiko AI)

Changes in v3:
- Block the DSP path selection if the firmware fails to load to prevent
  invalid routing states.

Changes in v2:
- Use snd_soc_component_update_bits() to prevent register overwriting.
  (Reported by Sashiko AI)
- Fix missing bit shift for default PEQ band. (Reported by Sashiko AI)

Neo Chang (2):
  ASoC: codecs: nau8360: Block DSP path selection when firmware load
    fails
  ASoC: codecs: nau8360: Fix AB-BA deadlock in mux update

 sound/soc/codecs/nau8360.c | 19 +++++++++++++------
 sound/soc/codecs/nau8360.h |  6 ++++++
 2 files changed, 19 insertions(+), 6 deletions(-)

-- 
2.25.1