[alsa-devel] Coherence of status structure after SYNC_PTR

[Ricardo Biehl Pasquali]

On Fri, Dec 28, 2018 at 01:21:24PM +0900, Takashi Sakamoto wrote:
> On Fri, Dec 28, 2018 at 12:45:49PM +0900, Takashi Sakamoto wrote:
> > I note that there're some levels of timestamp and autio timestamp.
> > Additionally, audio timestamp is updated only in any hardware/software IRQs,
> > thus it's not available with 'no-period-wakeup' runtime, FYI.
> 
> Oops. No, the audio timestamp can be updated in updating process of
> hardware pointer. A call of ioctl with SNDRV_PCM_IOCTL_STATUS and
> SNDRV_PCM_IOCTL_STATUS_EXT can return updated audio timestamp.

Thank you for the explanation!

Regarding the alsa-lib, pcm_hw, htimestamp():

Although not needed, adding a 'break' in the loop when
'mmap_status_fallbacked' is true would avoid another ioctl.

Cheers!

	pasquali