[PATCH 4/6] ASoC: codecs: lpass-rx-macro: switch cache to REGCACHE_MAPLE

[Srinivas Kandagatla]

REGCACHE_FLAT hides missing-default reads by returning the zero-
initialised cache slot instead of doing a bus read.  The caller
can't tell that value apart from a real hardware value, so any
un-defaulted, readable, non-volatile register that gets read
silently returns wrong data.  Since commit e062bdfdd6ad ("regmap:
warn users about uninitialized flat cache") regmap dev_warn_once()s
the first such miss, but any subsequent miss stays silent.

Switch to REGCACHE_MAPLE.  A cache miss returns -ENOENT and the
regmap core falls back to a real bus read, so the caller always
gets the true hardware value.  Write-cache behaviour is unchanged.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxxxxxxxx>
---
 sound/soc/codecs/lpass-rx-macro.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/soc/codecs/lpass-rx-macro.c b/sound/soc/codecs/lpass-rx-macro.c
index 4dac376927bb..fefd4430172a 100644
--- a/sound/soc/codecs/lpass-rx-macro.c
+++ b/sound/soc/codecs/lpass-rx-macro.c
@@ -1674,7 +1674,7 @@ static const struct regmap_config rx_regmap_config = {
 	.reg_bits = 16,
 	.val_bits = 32, /* 8 but with 32 bit read/write */
 	.reg_stride = 4,
-	.cache_type = REGCACHE_FLAT,
+	.cache_type = REGCACHE_MAPLE,
 	.max_register = RX_MAX_OFFSET,
 	.writeable_reg = rx_is_writeable_register,
 	.volatile_reg = rx_is_volatile_register,
-- 
2.53.0