ALSA: hda - Revive snd_hda_get_conn_list()
Manage the connection list cache using linked lists instead of
snd_array, and revive snd_hda_get_conn_list() again, so that we don't
have to keep the expanded values locally.
This will reduce the stack usage by recursive call of
snd_hda_get_conn_index() or parse_nid_path() of the generic parser.
The list management doesn't include any mutex protection, thus the
caller needs to take care of race appropriately.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index f4a0f9d..7eab3ae 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -334,20 +334,51 @@
}
EXPORT_SYMBOL_HDA(snd_hda_get_sub_nodes);
+/* connection list element */
+struct hda_conn_list {
+ struct list_head list;
+ int len;
+ hda_nid_t nid;
+ hda_nid_t conns[0];
+};
+
/* look up the cached results */
-static hda_nid_t *lookup_conn_list(struct snd_array *array, hda_nid_t nid)
+static struct hda_conn_list *
+lookup_conn_list(struct hda_codec *codec, 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)
+ struct hda_conn_list *p;
+ list_for_each_entry(p, &codec->conn_list, list) {
+ if (p->nid == nid)
return p;
- len = p[1];
- i += len + 2;
}
return NULL;
}
+static int add_conn_list(struct hda_codec *codec, hda_nid_t nid, int len,
+ const hda_nid_t *list)
+{
+ struct hda_conn_list *p;
+
+ p = kmalloc(sizeof(*p) + len * sizeof(hda_nid_t), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+ p->len = len;
+ p->nid = nid;
+ memcpy(p->conns, list, len * sizeof(hda_nid_t));
+ list_add(&p->list, &codec->conn_list);
+ return 0;
+}
+
+static void remove_conn_list(struct hda_codec *codec)
+{
+ while (!list_empty(&codec->conn_list)) {
+ struct hda_conn_list *p;
+ p = list_first_entry(&codec->conn_list, typeof(*p), list);
+ list_del(&p->list);
+ kfree(p);
+ }
+}
+
/* read the connection and add to the cache */
static int read_and_add_raw_conns(struct hda_codec *codec, hda_nid_t nid)
{
@@ -361,6 +392,49 @@
}
/**
+ * snd_hda_get_conn_list - get connection list
+ * @codec: the HDA codec
+ * @nid: NID to parse
+ * @len: number of connection list entries
+ * @listp: the pointer to store NID list
+ *
+ * Parses the connection list of the given widget and stores the pointer
+ * to the list of NIDs.
+ *
+ * Returns the number of connections, or a negative error code.
+ *
+ * Note that the returned pointer isn't protected against the list
+ * modification. If snd_hda_override_conn_list() might be called
+ * concurrently, protect with a mutex appropriately.
+ */
+int snd_hda_get_conn_list(struct hda_codec *codec, hda_nid_t nid,
+ const hda_nid_t **listp)
+{
+ bool added = false;
+
+ for (;;) {
+ int err;
+ const struct hda_conn_list *p;
+
+ /* if the connection-list is already cached, read it */
+ p = lookup_conn_list(codec, nid);
+ if (p) {
+ if (listp)
+ *listp = p->conns;
+ return p->len;
+ }
+ if (snd_BUG_ON(added))
+ return -EINVAL;
+
+ err = read_and_add_raw_conns(codec, nid);
+ if (err < 0)
+ return err;
+ added = true;
+ }
+}
+EXPORT_SYMBOL_HDA(snd_hda_get_conn_list);
+
+/**
* snd_hda_get_connections - copy connection list
* @codec: the HDA codec
* @nid: NID to parse
@@ -375,39 +449,20 @@
int snd_hda_get_connections(struct hda_codec *codec, hda_nid_t nid,
hda_nid_t *conn_list, int max_conns)
{
- struct snd_array *array = &codec->conn_lists;
- int len;
- hda_nid_t *p;
- bool added = false;
+ const hda_nid_t *list;
+ int len = snd_hda_get_conn_list(codec, nid, &list);
- again:
- mutex_lock(&codec->hash_mutex);
- len = -1;
- /* if the connection-list is already cached, read it */
- p = lookup_conn_list(array, nid);
- if (p) {
- len = p[1];
- if (conn_list && len > max_conns) {
+ if (len > 0 && conn_list) {
+ if (len > max_conns) {
snd_printk(KERN_ERR "hda_codec: "
"Too many connections %d for NID 0x%x\n",
len, nid);
- mutex_unlock(&codec->hash_mutex);
return -EINVAL;
}
- if (conn_list && len)
- memcpy(conn_list, p + 2, len * sizeof(hda_nid_t));
+ memcpy(conn_list, list, len * sizeof(hda_nid_t));
}
- mutex_unlock(&codec->hash_mutex);
- if (len >= 0)
- return len;
- if (snd_BUG_ON(added))
- return -EINVAL;
- len = read_and_add_raw_conns(codec, nid);
- if (len < 0)
- return len;
- added = true;
- goto again;
+ return len;
}
EXPORT_SYMBOL_HDA(snd_hda_get_connections);
@@ -519,15 +574,6 @@
return conns;
}
-static bool add_conn_list(struct snd_array *array, hda_nid_t nid)
-{
- hda_nid_t *p = snd_array_new(array);
- if (!p)
- return false;
- *p = nid;
- return true;
-}
-
/**
* snd_hda_override_conn_list - add/modify the connection-list to cache
* @codec: the HDA codec
@@ -543,28 +589,15 @@
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;
+ struct hda_conn_list *p;
- mutex_lock(&codec->hash_mutex);
- p = lookup_conn_list(array, nid);
- if (p)
- *p = -1; /* invalidate the old entry */
+ p = lookup_conn_list(codec, nid);
+ if (p) {
+ list_del(&p->list);
+ kfree(p);
+ }
- 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;
- mutex_unlock(&codec->hash_mutex);
- return 0;
-
- error_add:
- array->used = old_used;
- mutex_unlock(&codec->hash_mutex);
- return -ENOMEM;
+ return add_conn_list(codec, nid, len, list);
}
EXPORT_SYMBOL_HDA(snd_hda_override_conn_list);
@@ -582,10 +615,10 @@
int snd_hda_get_conn_index(struct hda_codec *codec, hda_nid_t mux,
hda_nid_t nid, int recursive)
{
- hda_nid_t conn[HDA_MAX_NUM_INPUTS];
+ const hda_nid_t *conn;
int i, nums;
- nums = snd_hda_get_connections(codec, mux, conn, ARRAY_SIZE(conn));
+ nums = snd_hda_get_conn_list(codec, mux, &conn);
for (i = 0; i < nums; i++)
if (conn[i] == nid)
return i;
@@ -1186,8 +1219,8 @@
snd_array_free(&codec->mixers);
snd_array_free(&codec->nids);
snd_array_free(&codec->cvt_setups);
- snd_array_free(&codec->conn_lists);
snd_array_free(&codec->spdif_out);
+ remove_conn_list(codec);
codec->bus->caddr_tbl[codec->addr] = NULL;
if (codec->patch_ops.free)
codec->patch_ops.free(codec);
@@ -1257,10 +1290,11 @@
snd_array_init(&codec->init_pins, sizeof(struct hda_pincfg), 16);
snd_array_init(&codec->driver_pins, sizeof(struct hda_pincfg), 16);
snd_array_init(&codec->cvt_setups, sizeof(struct hda_cvt_setup), 8);
- snd_array_init(&codec->conn_lists, sizeof(hda_nid_t), 64);
snd_array_init(&codec->spdif_out, sizeof(struct hda_spdif_out), 16);
snd_array_init(&codec->jacktbl, sizeof(struct hda_jack_tbl), 16);
snd_array_init(&codec->verbs, sizeof(struct hda_verb *), 8);
+ INIT_LIST_HEAD(&codec->conn_list);
+
INIT_DELAYED_WORK(&codec->jackpoll_work, hda_jackpoll_work);
#ifdef CONFIG_PM