Comment 4 for bug 668078

according to HDA specification

Input Delay is a 4-bit value representing the number of samples between when the sample is
received as an analog signal at the pin and when the digital representation is transmitted on the
High Definition Audio Link. This may be a “typical” value. If this is 0, the widgets along the
critical path should be queried, and each individual widget must report its individual delay.

Does PA developer mean HDA driver is still broken ?

alsa: work around slightly broken _delay implementations

Use snd_pcm_avail_delay() in pa_alsa_safe_delay() so that we can check the delay value against the avail value and patch it up when it looks invalid. Only do this for capture.

http://git.0pointer.de/?p=pulseaudio.git;a=commit;h=f29acfd0e0413a9bd126782763ee2dcf10357546