ASoC: soc-cache: Use reg_def_copy instead of reg_cache_default

Make sure to use codec->reg_def_copy instead of codec_drv->reg_cache_default
wherever necessary.  This change is necessary because in the next patch we
move the cache initialization code outside snd_soc_register_codec() and by that
time any data marked as __devinitconst such as the original reg_cache_default
array might have already been freed by the kernel.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 4649db6163b..a95d111a653 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -3434,6 +3434,7 @@ int snd_soc_register_codec(struct device *dev,
                 struct snd_soc_codec_driver *codec_drv,
                 struct snd_soc_dai_driver *dai_drv, int num_dai)
 {
+        size_t reg_size;
         struct snd_soc_codec *codec;
         int ret, i;
 
@@ -3469,6 +3470,19 @@ int snd_soc_register_codec(struct device *dev,
 
         /* allocate CODEC register cache */
         if (codec_drv->reg_cache_size && codec_drv->reg_word_size) {
+                reg_size = codec_drv->reg_cache_size * codec_drv->reg_word_size;
+                /* it is necessary to make a copy of the default register cache
+                 * because in the case of using a compression type that requires
+                 * the default register cache to be marked as __devinitconst the
+                 * 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 error_cache;
+                }
                 ret = snd_soc_cache_init(codec);
                 if (ret < 0) {
                         dev_err(codec->dev, "Failed to set cache compression type: %d\n",
@@ -3500,6 +3514,8 @@ int snd_soc_register_codec(struct device *dev,
 error_dais:
         snd_soc_cache_exit(codec);
 error_cache:
+        kfree(codec->reg_def_copy);
+        codec->reg_def_copy = NULL;
         kfree(codec->name);
         kfree(codec);
         return ret;
@@ -3534,6 +3550,7 @@ found:
         pr_debug("Unregistered codec '%s'\n", codec->name);
 
         snd_soc_cache_exit(codec);
+        kfree(codec->reg_def_copy);
         kfree(codec->name);
         kfree(codec);
 }