[alsa-devel] [PATCH] Fix buffer position for ATI SB4x0

[Takashi Iwai]

At Fri, 6 Jun 2008 11:52:32 -0300,
Mauro Carvalho Chehab wrote:
> 
> On Thu, 29 May 2008 16:20:21 +0200
> Takashi Iwai <tiwai at suse.de> wrote:
> 
> > At Thu, 29 May 2008 11:10:22 -0300,
> > Mauro Carvalho Chehab wrote:
> > > 
> > > ATI SB4x0 doesn't need any fix at position.
> > 
> > It's not about the position fixing but whether to use the
> > position-buffer.  The devices on the blacklist are the ones that have
> > no position buffer.  So, it would fall into LPIB mode, and this list
> > avoids it from the beginning.
> > 
> > > This patch solves the issue of receiving several clicks during capture on those
> > > devices.
> > > 
> > > Tested with a Gateway Notebook MX-6453.
> > 
> > The click noise is often a different problem.  Did you already try
> > the patch below?
> 
> The click seems associated to some residual samples inside the buffer. Here it
> is a sample of the king of click noise I'm hearing here (captured from CD input entry):
> 	http://linuxtv.org/~mchehab/snd.ogg

(I didn't check the ogg file yet, and just a wild guess)

Is it with dsnoop plugin?  With "default" PCM, ALSA uses dsnoop for
capture to allow multiplexing for HD-audio.  Does it happen with "hw"
or "plughw" PCM?


Takashi