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