[PATCH 4.2.y-ckt 123/206] ASoC: ak4642: Enable cache usage to fix crashes on resume

[Kamal Mostafa]

4.2.8-ckt12 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Mark Brown <broonie at kernel.org>

commit d3030d11961a8c103cf07aed59905276ddfc06c2 upstream.

The ak4642 driver is using a regmap cache sync to restore the
configuration of the chip on resume but (as Peter observed) does not
actually define a register cache which means that the resume is never
going to work and we trigger asserts in regmap.  Fix this by enabling
caching.

Reported-by: Geert Uytterhoeven <geert at linux-m68k.org>
Reported-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
Tested-by: Geert Uytterhoeven <geert+renesas at glider.be>
Signed-off-by: Mark Brown <broonie at kernel.org>
[ kamal: backport to 4.2-stable: no separate ak4643_regmap ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 sound/soc/codecs/ak4642.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/soc/codecs/ak4642.c b/sound/soc/codecs/ak4642.c
index 7c0f6552..d41708f 100644
--- a/sound/soc/codecs/ak4642.c
+++ b/sound/soc/codecs/ak4642.c
@@ -538,6 +538,7 @@ static const struct regmap_config ak4642_regmap = {
 	.max_register		= ARRAY_SIZE(ak4642_reg) + 1,
 	.reg_defaults		= ak4642_reg,
 	.num_reg_defaults	= ARRAY_SIZE(ak4642_reg),
+	.cache_type		= REGCACHE_RBTREE,
 };
 
 static const struct regmap_config ak4648_regmap = {
@@ -546,6 +547,7 @@ static const struct regmap_config ak4648_regmap = {
 	.max_register		= ARRAY_SIZE(ak4648_reg) + 1,
 	.reg_defaults		= ak4648_reg,
 	.num_reg_defaults	= ARRAY_SIZE(ak4648_reg),
+	.cache_type		= REGCACHE_RBTREE,
 };
 
 static const struct ak4642_drvdata ak4642_drvdata = {
-- 
2.7.4