[alsa-devel] [PATCH 0/3] Revised patch(es) for CLOCK_MONOTONIC_RAW timestamp

[Takashi Iwai]

At Mon, 14 Jul 2014 18:19:26 +0200,
Takashi Iwai wrote:
> 
> At Thu, 10 Jul 2014 15:04:15 +0200,
> Takashi Iwai wrote:
> > 
> > Hi,
> > 
> > here is a series of revised kernel patches for adding
> > CLOCK_MONOTONIC_RAW timestamp type.  In addition to Mark's original
> > patch, the new field is added to sw_params.
> > 
> > The corresponding alsa-lib patches will follow after these.
> 
> FWIW, I merged the patches with acks to topic/monotonic branch of
> sound git tree now.  It's merged to for-next branch.

And, now I'll revert the last part, the addition of sw_params again.

The addition to sw_params field would break the things when used with
an old alsa-lib, because the old alsa-lib sets the field to zero and
it overrides back to the gettimeofday from monotonic.

Unfortunately, there is no way in the kernel side whether the
user-space calls in the old sw_params or not.  We should have a field
or ioctl to set the protocol version the user-space talks, not only
the kernel talks.

For alsa-lib, we'd just need two new functions that are decoupled from
sw_params, e.g. snd_pcm_{get|set}_timestamp_type().

I'm going to submit new patches later.


Takashi