[PATCH 15/18] audio: Be more strict during audio backend initialisation

[Martin Kletzander]

Now that audiodev= is required and audio_init() will not be called
without and AudioDev we can remove the fallback functionality and error
out in case audio drivers fail initialisation or when the driver does
not exist.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
---
 audio/audio.c                   | 146 ++++++--------------------------
 docs/about/deprecated.rst       |   8 --
 docs/about/removed-features.rst |   8 ++
 3 files changed, 34 insertions(+), 128 deletions(-)

diff --git a/audio/audio.c b/audio/audio.c
index 97eb645764c1..c944cf817cf9 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -87,6 +87,8 @@ audio_driver *audio_driver_lookup(const char *name)
         }
     }
 
+    error_setg(&error_fatal, "Unknown audio driver `%s'", name);
+    /* Avoid compiler complaining that we do not return in non-void function */
     return NULL;
 }
 
@@ -104,8 +106,6 @@ const struct mixeng_volume nominal_volume = {
 #endif
 };
 
-static bool legacy_config = true;
-
 int audio_bug (const char *funcname, int cond)
 {
     if (cond) {
@@ -1532,31 +1532,27 @@ size_t audio_generic_read(HWVoiceIn *hw, void *buf, 
size_t size)
     return total;
 }
 
-static int audio_driver_init(AudioState *s, struct audio_driver *drv,
-                             bool msg, Audiodev *dev)
+static void audio_driver_init(AudioState *s, struct audio_driver *drv,
+                              Audiodev *dev)
 {
     s->drv_opaque = drv->init(dev);
 
-    if (s->drv_opaque) {
-        if (!drv->pcm_ops->get_buffer_in) {
-            drv->pcm_ops->get_buffer_in = audio_generic_get_buffer_in;
-            drv->pcm_ops->put_buffer_in = audio_generic_put_buffer_in;
-        }
-        if (!drv->pcm_ops->get_buffer_out) {
-            drv->pcm_ops->get_buffer_out = audio_generic_get_buffer_out;
-            drv->pcm_ops->put_buffer_out = audio_generic_put_buffer_out;
-        }
+    if (!s->drv_opaque) {
+        error_setg(&error_fatal, "Could not init `%s' audio driver", 
drv->name);
+    }
 
-        audio_init_nb_voices_out(s, drv);
-        audio_init_nb_voices_in(s, drv);
-        s->drv = drv;
-        return 0;
-    } else {
-        if (msg) {
-            dolog("Could not init `%s' audio driver\n", drv->name);
-        }
-        return -1;
+    if (!drv->pcm_ops->get_buffer_in) {
+        drv->pcm_ops->get_buffer_in = audio_generic_get_buffer_in;
+        drv->pcm_ops->put_buffer_in = audio_generic_put_buffer_in;
     }
+    if (!drv->pcm_ops->get_buffer_out) {
+        drv->pcm_ops->get_buffer_out = audio_generic_get_buffer_out;
+        drv->pcm_ops->put_buffer_out = audio_generic_put_buffer_out;
+    }
+
+    audio_init_nb_voices_out(s, drv);
+    audio_init_nb_voices_in(s, drv);
+    s->drv = drv;
 }
 
 static void audio_vm_change_state_handler (void *opaque, bool running,
@@ -1661,79 +1657,19 @@ static const VMStateDescription vmstate_audio = {
 
 static void audio_validate_opts(Audiodev *dev, Error **errp);
 
-static AudiodevListEntry *audiodev_find(
-    AudiodevListHead *head, const char *drvname)
-{
-    AudiodevListEntry *e;
-    QSIMPLEQ_FOREACH(e, head, next) {
-        if (strcmp(AudiodevDriver_str(e->dev->driver), drvname) == 0) {
-            return e;
-        }
-    }
-
-    return NULL;
-}
-
-/*
- * if we have dev, this function was called because of an -audiodev argument =>
- *   initialize a new state with it
- * if dev == NULL => legacy implicit initialization, return the already created
- *   state or create a new one
- */
-static AudioState *audio_init(Audiodev *dev, const char *name)
+static AudioState *audio_init(Audiodev *dev)
 {
     static bool atexit_registered;
-    size_t i;
-    int done = 0;
     const char *drvname = NULL;
     VMChangeStateEntry *e;
     AudioState *s;
-    struct audio_driver *driver;
-    /* silence gcc warning about uninitialized variable */
-    AudiodevListHead head = QSIMPLEQ_HEAD_INITIALIZER(head);
-
-    if (using_spice) {
-        /*
-         * When using spice allow the spice audio driver being picked
-         * as default.
-         *
-         * Temporary hack.  Using audio devices without explicit
-         * audiodev= property is already deprecated.  Same goes for
-         * the -soundhw switch.  Once this support gets finally
-         * removed we can also drop the concept of a default audio
-         * backend and this can go away.
-         */
-        driver = audio_driver_lookup("spice");
-        if (driver) {
-            driver->can_be_default = 1;
-        }
-    }
 
-    if (dev) {
-        /* -audiodev option */
-        legacy_config = false;
-        drvname = AudiodevDriver_str(dev->driver);
-    } else if (!QTAILQ_EMPTY(&audio_states)) {
-        if (!legacy_config) {
-            dolog("Device %s: audiodev default parameter is deprecated, please 
"
-                  "specify audiodev=%s\n", name,
-                  QTAILQ_FIRST(&audio_states)->dev->id);
-        }
-        return QTAILQ_FIRST(&audio_states);
-    } else {
-        /* legacy implicit initialization */
-        head = audio_handle_legacy_opts();
-        /*
-         * In case of legacy initialization, all Audiodevs in the list will 
have
-         * the same configuration (except the driver), so it doesn't matter 
which
-         * one we chose.  We need an Audiodev to set up AudioState before we 
can
-         * init a driver.  Also note that dev at this point is still in the
-         * list.
-         */
-        dev = QSIMPLEQ_FIRST(&head)->dev;
-        audio_validate_opts(dev, &error_abort);
+    if (!dev) {
+        error_setg(&error_abort, "Mandatory audiodev parameter required");
     }
 
+    drvname = AudiodevDriver_str(dev->driver);
+
     s = g_new0(AudioState, 1);
     s->dev = dev;
 
@@ -1763,37 +1699,7 @@ static AudioState *audio_init(Audiodev *dev, const char 
*name)
         s->nb_hw_voices_in = 0;
     }
 
-    if (drvname) {
-        driver = audio_driver_lookup(drvname);
-        if (driver) {
-            done = !audio_driver_init(s, driver, true, dev);
-        } else {
-            dolog ("Unknown audio driver `%s'\n", drvname);
-        }
-    } else {
-        for (i = 0; audio_prio_list[i]; i++) {
-            AudiodevListEntry *e = audiodev_find(&head, audio_prio_list[i]);
-            driver = audio_driver_lookup(audio_prio_list[i]);
-
-            if (e && driver) {
-                s->dev = dev = e->dev;
-                audio_validate_opts(dev, &error_abort);
-                done = !audio_driver_init(s, driver, false, dev);
-                if (done) {
-                    e->dev = NULL;
-                    break;
-                }
-            }
-        }
-    }
-    audio_free_audiodev_list(&head);
-
-    if (!done) {
-        driver = audio_driver_lookup("none");
-        done = !audio_driver_init(s, driver, false, dev);
-        assert(done);
-        dolog("warning: Using timer based audio emulation\n");
-    }
+    audio_driver_init(s, audio_driver_lookup(drvname), dev);
 
     if (dev->timer_period <= 0) {
         s->period_ticks = 1;
@@ -2120,7 +2026,7 @@ void audio_init_audiodevs(void)
     AudiodevListEntry *e;
 
     QSIMPLEQ_FOREACH(e, &audiodevs, next) {
-        audio_init(e->dev, NULL);
+        audio_init(e->dev);
     }
 }
 
@@ -2133,7 +2039,7 @@ static void audio_init_dummy(const char *id)
     dev->id = g_strdup(id);
 
     audio_validate_opts(dev, &error_abort);
-    audio_init(dev, NULL);
+    audio_init(dev);
 
     e->dev = dev;
     QSIMPLEQ_INSERT_TAIL(&audiodevs, e, next);
diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index 7ba71ebd3435..b2255319e347 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -31,14 +31,6 @@ backend settings instead of environment variables.  To ease 
migration to
 the new format, the ``-audiodev-help`` option can be used to convert
 the current values of the environment variables to ``-audiodev`` options.
 
-Creating sound card devices and vnc without ``audiodev=`` property (since 4.2)
-''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
-
-When not using the deprecated legacy audio config, each sound card
-should specify an ``audiodev=`` property.  Additionally, when using
-vnc, you should specify an ``audiodev=`` property if you plan to
-transmit audio through the VNC protocol.
-
 ``-chardev`` backend aliases ``tty`` and ``parport`` (since 6.0)
 ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
 
diff --git a/docs/about/removed-features.rst b/docs/about/removed-features.rst
index 086ba3edb042..f9eea4dda327 100644
--- a/docs/about/removed-features.rst
+++ b/docs/about/removed-features.rst
@@ -346,6 +346,14 @@ needs two devices (``-device intel-hda -device 
hda-duplex``) and
 pcspk-audiodev=<name>``.  And ``AC97`` and ``ES1370`` now have to be
 specified in uppercase.
 
+Creating sound card devices and vnc without ``audiodev=`` property (removed in 
7.1)
+'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+When not using the deprecated legacy audio config, each sound card
+should specify an ``audiodev=`` property.  Additionally, when using
+vnc, you should specify an ``audiodev=`` property if you plan to
+transmit audio through the VNC protocol.
+
 
 QEMU Machine Protocol (QMP) commands
 ------------------------------------
-- 
2.35.1