The current code might be a bit intriguing without having experienced the issue before, and might come up as a mistake.
Make explicit what's going on by adding a comment.
Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com --- sound/soc/sunxi/sun8i-codec.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/sound/soc/sunxi/sun8i-codec.c b/sound/soc/sunxi/sun8i-codec.c index 7a312168f864..3dd183be08a4 100644 --- a/sound/soc/sunxi/sun8i-codec.c +++ b/sound/soc/sunxi/sun8i-codec.c @@ -198,6 +198,17 @@ static int sun8i_set_fmt(struct snd_soc_dai *dai, unsigned int fmt) regmap_update_bits(scodec->regmap, SUN8I_AIF1CLK_CTRL, BIT(SUN8I_AIF1CLK_CTRL_AIF1_BCLK_INV), value << SUN8I_AIF1CLK_CTRL_AIF1_BCLK_INV); + + /* + * It appears that the DAI and the codec don't share the same + * polarity for the LRCK signal when they mean 'normal' and + * 'inverted' in the datasheet. + * + * Since the DAI here is our regular i2s driver that have been + * tested with way more codecs than just this one, it means + * that the codec probably gets it backward, and we have to + * invert the value here. + */ regmap_update_bits(scodec->regmap, SUN8I_AIF1CLK_CTRL, BIT(SUN8I_AIF1CLK_CTRL_AIF1_LRCK_INV), !value << SUN8I_AIF1CLK_CTRL_AIF1_LRCK_INV);