[Qemu-devel] [PATCH] audio: fix audio timer rate conversion bug

[Volker Rümelin]

Currently the default audio timer frequency is 10000Hz instead of
a period of 10000us. Also the audiodev timer-period property gets
converted like a frequency. Only handling of the legacy
QEMU_AUDIO_TIMER_PERIOD environment variable is correct because
it's actually a frequency.

With this patch the property timer-period is really a timer period
and QEMU_AUDIO_TIMER_PERIOD remains a frequency.

This fixes commit 71830221fb23388b32e6516c2fb7a698453a6c5a
-audiodev command line option basic implementation.

Signed-off-by: Volker Rümelin <address@hidden>
---
 audio/audio.c        | 2 +-
 audio/audio_legacy.c | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/audio/audio.c b/audio/audio.c
index 5fd9a58a80..2040762fef 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -1471,7 +1471,7 @@ static int audio_init(Audiodev *dev)
     if (dev->timer_period <= 0) {
         s->period_ticks = 1;
     } else {
-        s->period_ticks = NANOSECONDS_PER_SECOND / dev->timer_period;
+        s->period_ticks = dev->timer_period * SCALE_US;
     }
 
     e = qemu_add_vm_change_state_handler (audio_vm_change_state_handler, s);
diff --git a/audio/audio_legacy.c b/audio/audio_legacy.c
index 6d140119d9..2fd58cb8ef 100644
--- a/audio/audio_legacy.c
+++ b/audio/audio_legacy.c
@@ -26,6 +26,7 @@
 #include "audio_int.h"
 #include "qemu-common.h"
 #include "qemu/cutils.h"
+#include "qemu/timer.h"
 #include "qapi/error.h"
 #include "qapi/qapi-visit-audio.h"
 #include "qapi/visitor-impl.h"
@@ -338,8 +339,13 @@ static AudiodevListEntry *legacy_opt(const char *drvname)
     handle_per_direction(audio_get_pdo_in(e->dev), "QEMU_AUDIO_ADC_");
     handle_per_direction(audio_get_pdo_out(e->dev), "QEMU_AUDIO_DAC_");
 
+    /* Original description: Timer period in HZ (0 - use lowest possible) */
     get_int("QEMU_AUDIO_TIMER_PERIOD",
             &e->dev->timer_period, &e->dev->has_timer_period);
+    if (e->dev->has_timer_period && e->dev->timer_period) {
+        e->dev->timer_period = NANOSECONDS_PER_SECOND / 1000 /
+                               e->dev->timer_period;
+    }
 
     switch (e->dev->driver) {
     case AUDIODEV_DRIVER_ALSA:
-- 
2.16.4