ALSA: hda - Support sync after writing a verb

This patch adds a debug mode to make the codec communication
synchronous.  Define SND_HDA_SUPPORT_SYNC_WRITE in hda_codec.c,
and the call of snd_hda_codec_write*() will become synchronous,
i.e. wait for the reply from the codec at each time issuing a verb.

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

1 files changed, 61 insertions, 52 deletions

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 77385de01744..d1d5fb9d7afb 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -158,6 +158,38 @@ make_codec_cmd(struct hda_codec *codec, hda_nid_t nid, int direct,
         return val;
 }
 
+/*
+ * Send and receive a verb
+ */
+static int codec_exec_verb(struct hda_codec *codec, unsigned int cmd,
+                           unsigned int *res)
+{
+        struct hda_bus *bus = codec->bus;
+        int err, repeated = 0;
+
+        if (res)
+                *res = -1;
+        snd_hda_power_up(codec);
+        mutex_lock(&bus->cmd_mutex);
+ again:
+        err = bus->ops.command(bus, cmd);
+        if (!err) {
+                if (res) {
+                        *res = bus->ops.get_response(bus);
+                        if (*res == -1 && bus->rirb_error) {
+                                if (repeated++ < 1) {
+                                        snd_printd(KERN_WARNING "hda_codec: "
+                                           "Trying verb 0x%08x again\n", cmd);
+                                        goto again;
+                                }
+                        }
+                }
+        }
+        mutex_unlock(&bus->cmd_mutex);
+        snd_hda_power_down(codec);
+        return err;
+}
+
 /**
  * snd_hda_codec_read - send a command and get the response
  * @codec: the HDA codec
@@ -174,31 +206,18 @@ unsigned int snd_hda_codec_read(struct hda_codec *codec, hda_nid_t nid,
                                 int direct,
                                 unsigned int verb, unsigned int parm)
 {
-        struct hda_bus *bus = codec->bus;
-        unsigned int cmd, res;
-        int repeated = 0;
-
-        cmd = make_codec_cmd(codec, nid, direct, verb, parm);
-        snd_hda_power_up(codec);
-        mutex_lock(&bus->cmd_mutex);
- again:
-        if (!bus->ops.command(bus, cmd)) {
-                res = bus->ops.get_response(bus);
-                if (res == -1 && bus->rirb_error) {
-                        if (repeated++ < 1) {
-                                snd_printd(KERN_WARNING "hda_codec: "
-                                           "Trying verb 0x%08x again\n", cmd);
-                                goto again;
-                        }
-                }
-        } else
-                res = (unsigned int)-1;
-        mutex_unlock(&bus->cmd_mutex);
-        snd_hda_power_down(codec);
+        unsigned cmd = make_codec_cmd(codec, nid, direct, verb, parm);
+        unsigned int res;
+        codec_exec_verb(codec, cmd, &res);
         return res;
 }
 EXPORT_SYMBOL_HDA(snd_hda_codec_read);
 
+/* Define the below to send and receive verbs synchronously.
+ * If you often get any codec communication errors, this is worth to try.
+ */
+/* #define SND_HDA_SUPPORT_SYNC_WRITE */
+
 /**
  * snd_hda_codec_write - send a single command without waiting for response
  * @codec: the HDA codec
@@ -214,17 +233,13 @@ EXPORT_SYMBOL_HDA(snd_hda_codec_read);
 int snd_hda_codec_write(struct hda_codec *codec, hda_nid_t nid, int direct,
                          unsigned int verb, unsigned int parm)
 {
-        struct hda_bus *bus = codec->bus;
+        unsigned int cmd = make_codec_cmd(codec, nid, direct, verb, parm);
+#ifdef SND_HDA_SUPPORT_SYNC_WRITE
         unsigned int res;
-        int err;
-
-        res = make_codec_cmd(codec, nid, direct, verb, parm);
-        snd_hda_power_up(codec);
-        mutex_lock(&bus->cmd_mutex);
-        err = bus->ops.command(bus, res);
-        mutex_unlock(&bus->cmd_mutex);
-        snd_hda_power_down(codec);
-        return err;
+        return codec_exec_verb(codec, cmd, &res);
+#else
+        return codec_exec_verb(codec, cmd, NULL);
+#endif
 }
 EXPORT_SYMBOL_HDA(snd_hda_codec_write);
 
@@ -2281,28 +2296,22 @@ EXPORT_SYMBOL_HDA(snd_hda_create_spdif_in_ctls);
 int snd_hda_codec_write_cache(struct hda_codec *codec, hda_nid_t nid,
                               int direct, unsigned int verb, unsigned int parm)
 {
-        struct hda_bus *bus = codec->bus;
-        unsigned int res;
-        int err;
+        int err = snd_hda_codec_write(codec, nid, direct, verb, parm);
+        struct hda_cache_head *c;
+        u32 key;
 
-        res = make_codec_cmd(codec, nid, direct, verb, parm);
-        snd_hda_power_up(codec);
-        mutex_lock(&bus->cmd_mutex);
-        err = bus->ops.command(bus, res);
-        if (!err) {
-                struct hda_cache_head *c;
-                u32 key;
-                /* parm may contain the verb stuff for get/set amp */
-                verb = verb | (parm >> 8);
-                parm &= 0xff;
-                key = build_cmd_cache_key(nid, verb);
-                c = get_alloc_hash(&codec->cmd_cache, key);
-                if (c)
-                        c->val = parm;
-        }
-        mutex_unlock(&bus->cmd_mutex);
-        snd_hda_power_down(codec);
-        return err;
+        if (err < 0)
+                return err;
+        /* parm may contain the verb stuff for get/set amp */
+        verb = verb | (parm >> 8);
+        parm &= 0xff;
+        key = build_cmd_cache_key(nid, verb);
+        mutex_lock(&codec->bus->cmd_mutex);
+        c = get_alloc_hash(&codec->cmd_cache, key);
+        if (c)
+                c->val = parm;
+        mutex_unlock(&codec->bus->cmd_mutex);
+        return 0;
 }
 EXPORT_SYMBOL_HDA(snd_hda_codec_write_cache);