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

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>
Acked-by: Timur Tabi <timur@freescale.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 96bf381683f7..4274435853df 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -3507,11 +3507,13 @@ 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;
+                        }
                 }
         }