On Fri, Jun 6, 2008 at 3:54 PM, Christian Morales Vega <cmorve69@xxxxxxxx> wrote: > snd_pcm_avail_update() documentation says: "Using of this function is > useless for the standard read/write operations. Use it only for mmap > access. See to snd_pcm_delay." > > snd_pcm_delay() documentation says: "Note this function does not > update the actual r/w pointer for applications. The function > snd_pcm_avail_update() have to be called before any begin+commit > operation." > > My english is far from perfect, and so the problem can be that I > missunderstood the docs but: > 1- "Using of this function"? Should not be "Use of this function"? I would just say "This function is useless for...". > 2- Is snd_pcm_avail_update() really useless when not using mmap? The pcm.c example referenced right below that comment would indicate otherwise: http://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m.html#g41ca534658076885d9b077ad674750cd > I have a SB Live! where snd_pcm_delay() always returns the correct > value, without any need for snd_pcm_avail_update(). But the same code > in the same machine with an hda-intel AD1988 needs a call to > snd_pcm_avail_update() before snd_pcm_delay() to give the correct > result. Without it snd_pcm_delay() always returns the value that *was* > correct in the last snd_pcm_writei() call. > > So should the "application frame position" be always updated, or only > in read/write operations? In the first case AD1988 fails, in the > second case perhaps SB Live! is making too mucho work ;-) Is this with the latest ALSA HG sources? The SBLive driver is better working and more mature, so I'd presume it to be correct. Takashi-san? Lee _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
