(Audio) Implement write_avail always, even if just as a stub

audio/audio_driver.c

@@ -461,9 +461,7 @@ bool audio_driver_mute_toggle(void)
 static int audio_driver_write_avail(void)
 {
    driver_t *driver     = driver_get_ptr();
-   if (driver
+   if (driver && driver->audio)
-         && driver->audio
-         && driver->audio->write_avail)
       return driver->audio->write_avail(driver->audio_data);
    return 0;
 }
@@ -503,9 +501,7 @@ void audio_driver_readjust_input_rate(void)
 bool audio_driver_alive(void)
 {
    driver_t *driver     = driver_get_ptr();
-   if (driver
+   if (driver && driver->audio)
-         && driver->audio
-         && driver->audio->alive)
       return driver->audio->alive(driver->audio_data);
    return false;
 }
@@ -542,9 +538,7 @@ void audio_driver_set_nonblock_state(bool toggle)
 ssize_t audio_driver_write(const void *buf, size_t size)
 {
    driver_t *driver     = driver_get_ptr();
-   if (driver
+   if (driver && driver->audio)
-         && driver->audio
-         && driver->audio->write)
       return driver->audio->write(driver->audio_data, buf, size);
    return 0;
 }

audio/drivers/nullaudio.c

@@ -67,6 +67,12 @@ static bool null_audio_use_float(void *data)
    return true;
 }
 
+static size_t null_audio_write_avail(void *data)
+{
+   (void)data;
+   return 0;
+}
+
 audio_driver_t audio_null = {
    null_audio_init,
    null_audio_write,
@@ -77,6 +83,6 @@ audio_driver_t audio_null = {
    null_audio_free,
    null_audio_use_float,
    "null",
-   NULL,
+   null_audio_write_avail,
    NULL
 };

audio/drivers/ps3_audio.c

@@ -229,6 +229,12 @@ static bool ps3_audio_use_float(void *data)
    return true;
 }
 
+static size_t ps3_audio_write_avail(void *data)
+{
+   (void)data;
+   return 0;
+}
+
 audio_driver_t audio_ps3 = {
    ps3_audio_init,
    ps3_audio_write,
@@ -239,6 +245,6 @@ audio_driver_t audio_ps3 = {
    ps3_audio_free,
    ps3_audio_use_float,
    "ps3",
-   NULL,
+   ps3_audio_write_avail,
    NULL
 };

audio/drivers/roar.c

@@ -124,6 +124,12 @@ static bool ra_use_float(void *data)
    return false;
 }
 
+static size_t ra_write_avail(void *data)
+{
+   (void)data;
+   return 0;
+}
+
 audio_driver_t audio_roar = {
    ra_init,
    ra_write,
@@ -134,6 +140,6 @@ audio_driver_t audio_roar = {
    ra_free,
    ra_use_float,
    "roar",
-   NULL,
+   ra_write_avail,
    NULL
 };

audio/drivers/sdl_audio.c

@@ -225,12 +225,18 @@ static void sdl_audio_free(void *data)
    free(sdl);
 }
 
-static bool sdl_use_float(void *data)
+static bool sdl_audio_use_float(void *data)
 {
    (void)data;
    return false;
 }
 
+static size_t sdl_audio_write_avail(void *data)
+{
+   (void)data;
+   return 0;
+}
+
 audio_driver_t audio_sdl = {
    sdl_audio_init,
    sdl_audio_write,
@@ -239,12 +245,12 @@ audio_driver_t audio_sdl = {
    sdl_audio_alive,
    sdl_audio_set_nonblock_state,
    sdl_audio_free,
-   sdl_use_float,
+   sdl_audio_use_float,
 #ifdef HAVE_SDL2
    "sdl2",
 #else
    "sdl",
 #endif
-   NULL,
+   sdl_audio_write_avail,
    NULL
 };

audio/drivers/xenon360_audio.c

@@ -128,6 +128,12 @@ static bool xenon360_use_float(void *data)
    return false;
 }
 
+static size_t xenon360_write_avail(void *data)
+{
+   (void)data;
+   return 0;
+}
+
 audio_driver_t audio_xenon360 = {
    xenon360_audio_init,
    xenon360_audio_write,
@@ -138,6 +144,6 @@ audio_driver_t audio_xenon360 = {
    xenon360_audio_free,
    xenon360_use_float,
    "xenon360",
-   NULL,
+   xenon360_write_avail,
    NULL
 };