[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH v4 3/5] audio/hda: tweak timer adjust logic
From: |
Gerd Hoffmann |
Subject: |
[Qemu-devel] [PATCH v4 3/5] audio/hda: tweak timer adjust logic |
Date: |
Fri, 22 Jun 2018 13:11:58 +0200 |
We have some jitter in the audio timer call frequency and buffer sizes.
So it is rather pointless trying to be very exact, effect is a constant
up+down adjustment. So adjust only in case we are off too much.
Signed-off-by: Gerd Hoffmann <address@hidden>
---
hw/audio/hda-codec.c | 20 +++++++++++++-------
hw/audio/trace-events | 1 +
2 files changed, 14 insertions(+), 7 deletions(-)
diff --git a/hw/audio/hda-codec.c b/hw/audio/hda-codec.c
index a08516cbf8..870448a687 100644
--- a/hw/audio/hda-codec.c
+++ b/hw/audio/hda-codec.c
@@ -129,7 +129,6 @@ static void hda_codec_parse_fmt(uint32_t format, struct
audsettings *as)
#include "hda-codec-common.h"
#define HDA_TIMER_TICKS (SCALE_MS)
-#define MAX_CORR (SCALE_US * 100)
#define B_SIZE sizeof(st->buf)
#define B_MASK (sizeof(st->buf) - 1)
@@ -196,13 +195,20 @@ static inline int64_t hda_bytes_per_second(HDAAudioStream
*st)
static inline void hda_timer_sync_adjust(HDAAudioStream *st, int64_t
target_pos)
{
- int64_t corr =
- NANOSECONDS_PER_SECOND * target_pos / hda_bytes_per_second(st);
- if (corr > MAX_CORR) {
- corr = MAX_CORR;
- } else if (corr < -MAX_CORR) {
- corr = -MAX_CORR;
+ int64_t limit = B_SIZE / 8;
+ int64_t corr = 0;
+
+ if (target_pos > limit) {
+ corr = HDA_TIMER_TICKS;
}
+ if (target_pos < -limit) {
+ corr = -HDA_TIMER_TICKS;
+ }
+ if (corr == 0) {
+ return;
+ }
+
+ trace_hda_audio_adjust(st->node->name, target_pos);
atomic_fetch_add(&st->buft_start, corr);
}
diff --git a/hw/audio/trace-events b/hw/audio/trace-events
index 03340b9359..30112d97c4 100644
--- a/hw/audio/trace-events
+++ b/hw/audio/trace-events
@@ -21,3 +21,4 @@ milkymist_ac97_out_cb_transferred(int transferred)
"transferred %d"
# hw/audio/hda-codec.c
hda_audio_running(const char *stream, int nr, bool running) "st %s, nr %d, run
%d"
hda_audio_format(const char *stream, int chan, const char *fmt, int freq) "st
%s, %d x %s @ %d Hz"
+hda_audio_adjust(const char *stream, int pos) "st %s, pos %d"
--
2.9.3