RE: snd-powermac produces only low quality dirty so

[Giuliano Pochini <pochini@shiny.it>]

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On 14-Dec-2004 Olaf Hering wrote:

> All 2.6 versions I tried so far produce only "dirty" low quality sound
> when playing mp3 with xmms with either the alsa or oss plugin.
> But it works as expected when I use dmasound_pmac and the liboss plugin.
>
> Any ideas how to debug it?

It seems that the chip is not happy with some period/buffer sizes.
Someone was trying to find the right constraints to set for those
parameters. Maybe the attached patch fixes it (untested).



--
Giuliano.

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--- alsa-kernel/ppc/pmac.c__	Wed Dec 15 10:15:37 2004
+++ alsa-kernel/ppc/pmac.c	Wed Dec 15 10:37:15 2004
@@ -538,6 +538,11 @@
 	runtime->private_data = rec;
 	rec->substream = subs;
 
+	if ((i = snd_pcm_hw_constraint_pow2(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE
)) < 0)
+		return i;
+	if ((i = snd_pcm_hw_constraint_pow2(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_SIZE
)) < 0)
+		return i;
+
 #if 0 /* FIXME: still under development.. */
 	snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
 			    snd_pmac_hw_rule_rate, chip, rec->stream, -1);