1 files changed, 17 insertions, 5 deletions

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 8b79d90efdc1..5299932db0b6 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -84,7 +84,7 @@ static int run_delayed_work(struct delayed_work *dwork)
 /* codec register dump */
 static ssize_t soc_codec_reg_show(struct snd_soc_codec *codec, char *buf)
 {
-        int i, step = 1, count = 0;
+        int ret, i, step = 1, count = 0;
 
         if (!codec->reg_cache_size)
                 return 0;
@@ -101,12 +101,24 @@ static ssize_t soc_codec_reg_show(struct snd_soc_codec *codec, char *buf)
                 if (count >= PAGE_SIZE - 1)
                         break;
 
-                if (codec->display_register)
+                if (codec->display_register) {
                         count += codec->display_register(codec, buf + count,
                                                          PAGE_SIZE - count, i);
-                else
-                        count += snprintf(buf + count, PAGE_SIZE - count,
-                                          "%4x", codec->read(codec, i));
+                } else {
+                        /* If the read fails it's almost certainly due to
+                         * the register being volatile and the device being
+                         * powered off.
+                         */
+                        ret = codec->read(codec, i);
+                        if (ret >= 0)
+                                count += snprintf(buf + count,
+                                                  PAGE_SIZE - count,
+                                                  "%4x", ret);
+                        else
+                                count += snprintf(buf + count,
+                                                  PAGE_SIZE - count,
+                                                  "<no data: %d>", ret);
+                }
 
                 if (count >= PAGE_SIZE - 1)
                         break;