[pulseaudio-discuss] [PATCH] alsa-util: Use time stamp config only for alsa versions >= 1.1.0

[Arun Raghavan]

On Wed, 16 May 2018, at 12:42 AM, Pierre-Louis Bossart wrote:
> On 5/15/18 8:12 AM, Arun Raghavan wrote:
> > On Tue, 15 May 2018, at 11:30 AM, Georg Chini wrote:
> >> The commit "alsa-util: Set ALSA report_delay flag in pa_alsa_safe_delay()"
> >> broke the build on ALSA versions below 1.1.0 because the time stamp
> >> configuration function was introduced in 1.1.0.
> >>
> >> This patch makes the usage of snd_pcm_status_set_audio_htstamp_config()
> >> dependent on ALSA version.
> >> ---
> >>   src/modules/alsa/alsa-util.c | 8 +++++++-
> >>   1 file changed, 7 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/src/modules/alsa/alsa-util.c b/src/modules/alsa/alsa-util.c
> >> index b91a0e98..41134ea5 100644
> >> --- a/src/modules/alsa/alsa-util.c
> >> +++ b/src/modules/alsa/alsa-util.c
> >> @@ -1187,7 +1187,9 @@ int pa_alsa_safe_delay(snd_pcm_t *pcm,
> >> snd_pcm_status_t *status, snd_pcm_sframes
> >>       size_t abs_k;
> >>       int err;
> >>       snd_pcm_sframes_t avail = 0;
> >> +#if (SND_LIB_VERSION >= ((1<<16)|(1<<8)|0)) /* API additions in 1.1.0
> >> */
> >>       snd_pcm_audio_tstamp_config_t tstamp_config;
> >> +#endif
> >>   
> >>       pa_assert(pcm);
> >>       pa_assert(delay);
> >> @@ -1201,11 +1203,15 @@ int pa_alsa_safe_delay(snd_pcm_t *pcm,
> >> snd_pcm_status_t *status, snd_pcm_sframes
> >>        * avail, delay and timestamp values in a single kernel call to
> >> improve
> >>        * timer-based scheduling */
> >>   
> >> +#if (SND_LIB_VERSION >= ((1<<16)|(1<<8)|0)) /* API additions in 1.1.0 */
> >> +
> >>       /* The time stamp configuration needs to be set so that the
> >> -     * ALSA code will use the internal delay reported by the driver */
> >> +     * ALSA code will use the internal delay reported by the driver.
> >> +     * The time stamp configuration was introduced in alsa version 1.1.0. */
> >>       tstamp_config.type_requested = 1; /* ALSA default time stamp type */
> >>       tstamp_config.report_delay = 1;
> >>       snd_pcm_status_set_audio_htstamp_config(status, &tstamp_config);
> >> +#endif
> >>   
> >>       if ((err = snd_pcm_status(pcm, status)) < 0)
> >>           return err;
> >> -- 
> > 
> > Looks good.
> 
> Takashi and I mentioned it's not quite right but what can I say...

I check with Georg before acking the original commit and his impression was that it was fine. Do we have consensus on eBay this should be?

-- Arun