Re: [ALSA BUG] VIA 82xx broken by 0.9.0rc7 patch

[Takashi Iwai <tiwai@suse.de>]

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At 24 Mar 2003 10:40:03 -0500,
Kristofer T. Karas <ktk@bigfoot.com> wrote:
> 
> Hello Takashi,
> 
> I upgrade my via-82xx driver from 0.9.0rc6 to 0.9.2 and found that the
> sound quality patch (applied somewhere in the 0.9.0rc1 timeframe) seemed
> to have been lost/reverted.  Working backwards to find the point at
> which things broke, it appears to be your kernel driver patch made in
> mid December (between 0.9.0rc6 and 0.9.0rc7).  I browsed alsa-devel and
> alsa-users to see if this had been reported previously, but I have seen
> little other than random bug-reports on alsa-user (most recently one
> about "Noise").
> 
> Although the 8233 driver "functioned" throughout most of 0.9.0beta...,
> sound quality was dreadful.  The output seemed to be a combination of
> being clipped and passed through a flanger.  The beat frequency of the
> "flanger" effect could be reduced to tolerable levels if the input
> sampling frequency was set to 48KHz rather than 44.1 or whatever.
> 
> Then, sometime in the 0.9.0rc1 timeframe (sorry, I don't remember just
> which version) a patch to 8233 fixed the problem.  That is, until
> 0.9.0rc7.
> 
> Since you're the submitter of the patch in question, I thought I'd send
> this report your way...

could you try the attached patch?  it might solve the problem if you
mentioned about OSS applications.

except for such a hidden bug, the difference between 0.9.0rc6 and rc7
is the use of the DSX channels as the first pcm device.  if the above
patch doesn't fix, please try to use hw:0,1 (for alsa native) or
/dev/adsp (for oss) as the sound device.

if the second pcm device works, then your chip model doesn't support
DSX channels well.  maybe it's better to put the module option to
specify the chip model explicitly...


Takashi

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Index: alsa-kernel/pci/via82xx.c
===================================================================
RCS file: /suse/tiwai/cvs/alsa/alsa-kernel/pci/via82xx.c,v
retrieving revision 1.38
diff -u -r1.38 via82xx.c
--- alsa-kernel/pci/via82xx.c	3 Mar 2003 16:56:44 -0000	1.38
+++ alsa-kernel/pci/via82xx.c	25 Mar 2003 11:57:59 -0000
@@ -843,12 +843,11 @@
 	int changed = 0;
 
 	spin_lock(&rec->lock);
-	if (rec->rate) {
-		if (rec->rate != rate && rec->used > 1) {
+	if (rec->rate != rate) {
+		if (rec->rate && rec->used > 1) { /* already set */
 			spin_unlock(&rec->lock);
 			return -EINVAL;
 		}
-	} else {
 		rec->rate = rate;
 		changed = 1;
 	}