[PATCH 4.4 043/114] ASoC: wm8940: Enable cache usage to fix crashes on resume

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

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[ Upstream commit 50c7a0ef2d97e56c7ce2f1ea5fe1d8e25aadc1bb ]

The wm8940 driver is using a regmap cache sync to restore the
configuration of the chip when switching from OFF to STANDBY, but does
not actually define a register cache which means that the restore is
never going to work and we trigger asserts in regmap.  Fix this by
enabling caching.

Based on commit d3030d11961a8c10 ("ASoC: ak4642: Enable cache usage to
fix crashes on resume") by Mark Brown <broonie@xxxxxxxxxx>.

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Acked-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 sound/soc/codecs/wm8940.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sound/soc/codecs/wm8940.c b/sound/soc/codecs/wm8940.c
index f6f9395ea38e..1c600819f768 100644
--- a/sound/soc/codecs/wm8940.c
+++ b/sound/soc/codecs/wm8940.c
@@ -743,6 +743,7 @@ static const struct regmap_config wm8940_regmap = {
 	.max_register = WM8940_MONOMIX,
 	.reg_defaults = wm8940_reg_defaults,
 	.num_reg_defaults = ARRAY_SIZE(wm8940_reg_defaults),
+	.cache_type = REGCACHE_RBTREE,
 
 	.readable_reg = wm8940_readable_register,
 	.volatile_reg = wm8940_volatile_register,
-- 
2.17.1