At Thu, 14 Jul 2011 14:13:48 +0800, Raymond Yau wrote:

...

+config SND_HDA_PREALLOC_SIZE

• int "Pre-allocated buffer size for HD-audio driver"
• range 0 32768
• default 64
• help

•  Speficies the default pre-allocated buffer-size in kB for
  

•  HD-audio driver.  A larger buffer (e.g. 2048) is preferred
  

•  for systems with PulseAudio.  The default 64 is chosen just
  

•  from the compatibility reason.
  

• range 0 32768

•  range 64 32768
  
  

It seem that the minimum range cannot be zero

Zero is a valid value. Then the buffer isn't pre-allocated but allocated at each time PCM is opened (more exactly hw_params is called).

Does current PA server still work with sound drivers with 64K buffer ?

Yes.

Takashi