26 Jun
2012
26 Jun
'12
12:27 p.m.
Zhen Fu wrote:
when DMA handler called snd_pcm_period_elapsed, so I want to know how about update hw_ptr in ALSA.
snd_pcm_period_elapsed() calls snd_pcm_update_hw_ptr0(), which calls your driver's .pointer callback. The value returned by that callback essentially is the hw_ptr (although it doesn't wrap around at the end of the buffer).
Why do you care about hw_ptr?
Regards, Clemens