[alsa-devel] [PATCH v2 10/10] ALSA: hda: replace .wallclock by .get_time_info

Raymond Yau superquad.vortex2 at gmail.com
Sat Dec 20 07:07:44 CET 2014


>
> No real functional change, only take wall clock and system time
> in same routine and add accuracy report.
>
>
> +               *audio_ts = ns_to_timespec(nsec);
> +
> +               audio_tstamp_report->actual_type =
SNDRV_PCM_AUDIO_TSTAMP_TYPE_LINK;
> +               audio_tstamp_report->accuracy_report = 1; /* rest of
structure is valid */
> +               audio_tstamp_report->accuracy_m = 42; /* 24 MHz WallClock
== 42ns resolution */
> +               audio_tstamp_report->accuracy_e = 0;
> +

Do you mean wall clock run at 48000 * 500 Hz ? 42.666ns

Those aureal sound cards also can provide time stamp using VORTEX_SMP_TIME
mmio register which tick at 48000 * 256 Hz ?


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