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audio/hda: tweak timer adjust logic

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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 <kraxel@redhat.com>
Message-id: 20180622111200.30561-4-kraxel@redhat.com
This commit is contained in:
Gerd Hoffmann 2018-06-22 13:11:58 +02:00
parent 0a373bb310
commit 8ced066923
2 changed files with 14 additions and 7 deletions
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20
hw/audio/hda-codec.c
View File

@ -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);
}

1
hw/audio/trace-events
View File

@ -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"