Re: [PATCH v2 00/10] audio timestamping evolutions

[Jaroslav Kysela <perex@perex.cz>]

Dne 19.12.2014 v 18:25 Pierre-Louis Bossart napsal(a):
> This series of patches was inspired by recent threads on the alsa
> mailing list, as well issues detected with existing and upcoming
> hardware:

I don't like some aspects in the interface:

1) ext_info member is not required - the standard info field
   has enough free bits
2) the whole struct snd_pcm_status is R/O -
   _IOR('A', 0x20, struct snd_pcm_status); I believe that it's much
   better to add new audio_tstamp_type to sw_params, but see (4)
3) accuracy - I would use uint64_t and report accuracy in pico-seconds
   (range from 0 picoseconds to 18446744 seconds); yes, use next bytes
   from the reserved part of status struct. the __u32 might be used only
   for flags
4) if there is a motivation to call / obtain timestamps for multiple
   purposes (audio tstamp types), then offer to return all these
   timestamps in one shot rather than do multiple queries (again, use
   reserved bytes)

			Thanks,
				Jaroslav

-- 
Jaroslav Kysela <perex@perex.cz>
Linux Kernel Sound Maintainer
ALSA Project; Red Hat, Inc.