[ALSA] cleanup and error reporting for sound/core/init.c

Make the control flow clear with indentation, adds some comments
and improves error reporting.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 14 insertions, 8 deletions

diff --git a/sound/core/init.c b/sound/core/init.c
index a4cc6b155ae9..db6103733742 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -114,22 +114,28 @@ struct snd_card *snd_card_new(int idx, const char *xid,
         if (idx < 0) {
                 int idx2;
                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
+                        /* idx == -1 == 0xffff means: take any free slot */
                         if (~snd_cards_lock & idx & 1<<idx2) {
                                 idx = idx2;
                                 if (idx >= snd_ecards_limit)
                                         snd_ecards_limit = idx + 1;
                                 break;
                         }
-        } else if (idx < snd_ecards_limit) {
-                if (snd_cards_lock & (1 << idx))
-                        err = -ENODEV;  /* invalid */
-        } else if (idx < SNDRV_CARDS)
-                snd_ecards_limit = idx + 1; /* increase the limit */
-        else
-                err = -ENODEV;
+        } else {
+                 if (idx < snd_ecards_limit) {
+                        if (snd_cards_lock & (1 << idx))
+                                err = -EBUSY;   /* invalid */
+                } else {
+                        if (idx < SNDRV_CARDS)
+                                snd_ecards_limit = idx + 1; /* increase the limit */
+                        else
+                                err = -ENODEV;
+                }
+        }
         if (idx < 0 || err < 0) {
                 mutex_unlock(&snd_card_mutex);
-                snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i)\n", idx, snd_ecards_limit - 1);
+                snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i), error: %d\n",
+                         idx, snd_ecards_limit - 1, err);
                 goto __error;
         }
         snd_cards_lock |= 1 << idx;             /* lock it */