ALSA: hda - Add snd_hda_override_conn_list() helper function

Add a function to add/modify the connection-list cache entry.
It'll be useful to fix a buggy hardware result.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

2 files changed, 71 insertions, 30 deletions

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 7f8502388a82..d0deab1ed510 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -310,10 +310,23 @@ EXPORT_SYMBOL_HDA(snd_hda_get_sub_nodes);
 
 static int _hda_get_connections(struct hda_codec *codec, hda_nid_t nid,
                                 hda_nid_t *conn_list, int max_conns);
-static bool add_conn_list(struct snd_array *array, hda_nid_t nid);
+
+/* look up the cached results */
+static hda_nid_t *lookup_conn_list(struct snd_array *array, hda_nid_t nid)
+{
+        int i, len;
+        for (i = 0; i < array->used; ) {
+                hda_nid_t *p = snd_array_elem(array, i);
+                if (nid == *p)
+                        return p;
+                len = p[1];
+                i += len + 2;
+        }
+        return NULL;
+}
 
 /**
- * snd_hda_get_connections - get connection list
+ * snd_hda_get_conn_list - get connection list
  * @codec: the HDA codec
  * @nid: NID to parse
  * @listp: the pointer to store NID list
@@ -327,42 +340,31 @@ int snd_hda_get_conn_list(struct hda_codec *codec, hda_nid_t nid,
                           const hda_nid_t **listp)
 {
         struct snd_array *array = &codec->conn_lists;
-        int i, len, old_used;
+        int len, err;
         hda_nid_t list[HDA_MAX_CONNECTIONS];
         hda_nid_t *p;
+        bool added = false;
 
-        /* look up the cached results */
-        for (i = 0; i < array->used; ) {
-                p = snd_array_elem(array, i);
-                len = p[1];
-                if (nid == *p) {
-                        if (listp)
-                                *listp = p + 2;
-                        return len;
-                }
-                i += len + 2;
+ again:
+        /* if the connection-list is already cached, read it */
+        p = lookup_conn_list(array, nid);
+        if (p) {
+                if (listp)
+                        *listp = p + 2;
+                return p[1];
         }
+        if (snd_BUG_ON(added))
+                return -EINVAL;
 
+        /* read the connection and add to the cache */
         len = _hda_get_connections(codec, nid, list, HDA_MAX_CONNECTIONS);
         if (len < 0)
                 return len;
-
-        /* add to the cache */
-        old_used = array->used;
-        if (!add_conn_list(array, nid) || !add_conn_list(array, len))
-                goto error_add;
-        for (i = 0; i < len; i++)
-                if (!add_conn_list(array, list[i]))
-                        goto error_add;
-
-        p = snd_array_elem(array, old_used);
-        if (listp)
-                *listp = p + 2;
-        return len;
-                
- error_add:
-        array->used = old_used;
-        return -ENOMEM;
+        err = snd_hda_override_conn_list(codec, nid, len, list);
+        if (err < 0)
+                return err;
+        added = true;
+        goto again;
 }
 EXPORT_SYMBOL_HDA(snd_hda_get_conn_list);
 
@@ -503,6 +505,43 @@ static bool add_conn_list(struct snd_array *array, hda_nid_t nid)
 }
 
 /**
+ * snd_hda_override_conn_list - add/modify the connection-list to cache
+ * @codec: the HDA codec
+ * @nid: NID to parse
+ * @len: number of connection list entries
+ * @list: the list of connection entries
+ *
+ * Add or modify the given connection-list to the cache.  If the corresponding
+ * cache already exists, invalidate it and append a new one.
+ *
+ * Returns zero or a negative error code.
+ */
+int snd_hda_override_conn_list(struct hda_codec *codec, hda_nid_t nid, int len,
+                               const hda_nid_t *list)
+{
+        struct snd_array *array = &codec->conn_lists;
+        hda_nid_t *p;
+        int i, old_used;
+
+        p = lookup_conn_list(array, nid);
+        if (p)
+                *p = -1; /* invalidate the old entry */
+
+        old_used = array->used;
+        if (!add_conn_list(array, nid) || !add_conn_list(array, len))
+                goto error_add;
+        for (i = 0; i < len; i++)
+                if (!add_conn_list(array, list[i]))
+                        goto error_add;
+        return 0;
+
+ error_add:
+        array->used = old_used;
+        return -ENOMEM;
+}
+EXPORT_SYMBOL_HDA(snd_hda_override_conn_list);
+
+/**
  * snd_hda_get_conn_index - get the connection index of the given NID
  * @codec: the HDA codec
  * @mux: NID containing the list
diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h
index 10d500d2ba33..e6bc16f66bce 100644
--- a/sound/pci/hda/hda_codec.h
+++ b/sound/pci/hda/hda_codec.h
@@ -905,6 +905,8 @@ int snd_hda_get_connections(struct hda_codec *codec, hda_nid_t nid,
                             hda_nid_t *conn_list, int max_conns);
 int snd_hda_get_conn_list(struct hda_codec *codec, hda_nid_t nid,
                           const hda_nid_t **listp);
+int snd_hda_override_conn_list(struct hda_codec *codec, hda_nid_t nid, int nums,
+                          const hda_nid_t *list);
 int snd_hda_get_conn_index(struct hda_codec *codec, hda_nid_t mux,
                            hda_nid_t nid, int recursive);
 int snd_hda_query_supported_pcm(struct hda_codec *codec, hda_nid_t nid,