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>

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 77385de..d1d5fb9 100644 (file)
--- 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);