[PATCH] ASoC: soc-core: Add support for NULL default register caches

[Dimitris Papastamos <dp@opensource.wolfsonmicro.com>]

The infrastructure for handling NULL default register maps is already
included in the soc-cache code, just ensure that we don't try to dereference
a NULL pointer while accessing a NULL register cache.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
---
 sound/soc/soc-core.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index bac7291..a9f19c1 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -3503,11 +3503,13 @@ int snd_soc_register_codec(struct device *dev,
 		 * kernel might have freed the array by the time we initialize
 		 * the cache.
 		 */
-		codec->reg_def_copy = kmemdup(codec_drv->reg_cache_default,
-					      reg_size, GFP_KERNEL);
-		if (!codec->reg_def_copy) {
-			ret = -ENOMEM;
-			goto fail;
+		if (codec_drv->reg_cache_default) {
+			codec->reg_def_copy = kmemdup(codec_drv->reg_cache_default,
+						      reg_size, GFP_KERNEL);
+			if (!codec->reg_def_copy) {
+				ret = -ENOMEM;
+				goto fail;
+			}
 		}
 	}
 
-- 
1.7.3.5