| Message ID | 1554473393-5757-1-git-send-email-twischer@de.adit-jv.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | pcm: null: Do not allow a period size of 0 | expand |
On Fri, 05 Apr 2019 16:09:53 +0200, <twischer@de.adit-jv.com> wrote: > > From: Timo Wischer <twischer@de.adit-jv.com> > > Some applications do not expect that get_period_size_min() could > return 0. Therefore these applications cannot use the null plugin without > this patch. > Due to there is no use case for having a period size of 0 this patch > disallows a period size of 0 when using the null plugin. > > Signed-off-by: Timo Wischer <twischer@de.adit-jv.com> > --- > src/pcm/pcm_null.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/src/pcm/pcm_null.c b/src/pcm/pcm_null.c > index ff61624..c95fad8 100644 > --- a/src/pcm/pcm_null.c > +++ b/src/pcm/pcm_null.c > @@ -261,7 +261,18 @@ static snd_pcm_sframes_t snd_pcm_null_mmap_commit(snd_pcm_t *pcm, > > static int snd_pcm_null_hw_refine(snd_pcm_t *pcm ATTRIBUTE_UNUSED, snd_pcm_hw_params_t *params) > { > - int err = snd_pcm_hw_refine_soft(pcm, params); > + int err; > + > + /* Do not return a period size of 0 because for example portaudio cannot > + * handle it. In addition such small buffers would only increase the CPU > + * load but there is no benefit when throwing the samples anyway away. > + */ > + err = _snd_pcm_hw_param_set_min(params, SND_PCM_HW_PARAM_PERIOD_SIZE, > + 32, 0); Why 32? This is a virtual device, hence we don't need to set any practical limit. If the zero is harmfull, the next preferable alternative is 1, when logically thinking. Or does it cause a problem? thanks, Takashi
diff --git a/src/pcm/pcm_null.c b/src/pcm/pcm_null.c index ff61624..c95fad8 100644 --- a/src/pcm/pcm_null.c +++ b/src/pcm/pcm_null.c @@ -261,7 +261,18 @@ static snd_pcm_sframes_t snd_pcm_null_mmap_commit(snd_pcm_t *pcm, static int snd_pcm_null_hw_refine(snd_pcm_t *pcm ATTRIBUTE_UNUSED, snd_pcm_hw_params_t *params) { - int err = snd_pcm_hw_refine_soft(pcm, params); + int err; + + /* Do not return a period size of 0 because for example portaudio cannot + * handle it. In addition such small buffers would only increase the CPU + * load but there is no benefit when throwing the samples anyway away. + */ + err = _snd_pcm_hw_param_set_min(params, SND_PCM_HW_PARAM_PERIOD_SIZE, + 32, 0); + if (err < 0) + return err; + + err = snd_pcm_hw_refine_soft(pcm, params); params->info = SND_PCM_INFO_MMAP | SND_PCM_INFO_MMAP_VALID | SND_PCM_INFO_RESUME | SND_PCM_INFO_PAUSE; params->fifo_size = 0;