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

[Mauro Carvalho Chehab]

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've started/stopped the CD some times (with cdplay). When volume goes to zero,
after an "echoed click", it disappears.

I've did some trials with position_fix changes, but nothing solved. So, my
previous patch were wrong. The click is somewhere else (still, I suspect that
it is linked to the buffer handling).

Cheers,
Mauro