ALSA: core: Allow card id change to the same string

When user want to change the card id to the same string
on the card via /sys/class/sound/cardX/id, do not
report error. Instead return with success without
doing anything.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 7 insertions, 2 deletions

diff --git a/sound/core/init.c b/sound/core/init.c
index ec4a50ce5656..2de45fbd70fb 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -607,11 +607,16 @@ card_id_store_attr(struct device *dev, struct device_attribute *attr,
                 return -EEXIST;
         }
         for (idx = 0; idx < snd_ecards_limit; idx++) {
-                if (snd_cards[idx] && !strcmp(snd_cards[idx]->id, buf1))
-                        goto __exist;
+                if (snd_cards[idx] && !strcmp(snd_cards[idx]->id, buf1)) {
+                        if (card == snd_cards[idx])
+                                goto __ok;
+                        else
+                                goto __exist;
+                }
         }
         strcpy(card->id, buf1);
         snd_info_card_id_change(card);
+__ok:
         mutex_unlock(&snd_card_mutex);
 
         return count;