On Wed, Mar 28, 2007 at 10:03:30PM +0200, Rask Ingemann Lambertsen wrote:
>
> It is clearly only half-duplex when the DSP is in high-speed mode. It is
> less clear what will happen in low-speed mode if one tries to capture during
> playback or vice versa. I don't know if the Jazz16 needs high-speed mode at
> all, so I'll do some testing.
It plays fine in low-speed mode even at 45454 Hz and in stereo.
> Note that my board is rather anonymous. For all I know, it could be an
> OEM one.
FCC-ID KRN3261 leads me to KTL Research Limited, Hong Kong.
[8-bit playback through 16-bit DMA channel]
> Playback sounds normal except for a click for each "pointer ..." message.
> Any ideas? /proc/interrupts increments by 11.
This additional patch fixes it:
--- linux-2.6.20/sound/isa/sb/sb8_main.c~ 2007-03-29 00:48:56.000000000 +0200
+++ linux-2.6.20/sound/isa/sb/sb8_main.c 2007-03-29 00:48:56.000000000 +0200
@@ -228,6 +228,8 @@ static int snd_sb8_playback_prepare(stru
snd_sbdsp_command(chip, 256 - runtime->rate_den);
}
if (chip->playback_format != SB_DSP_OUTPUT) {
+ if (dma > 3)
+ count /= 2;
count--;
snd_sbdsp_command(chip, SB_DSP_BLOCK_SIZE);
snd_sbdsp_command(chip, count & 0xff);
@@ -350,6 +352,8 @@ static int snd_sb8_capture_prepare(struc
snd_sbdsp_command(chip, 256 - runtime->rate_den);
}
if (chip->capture_format != SB_DSP_OUTPUT) {
+ if (dma > 3)
+ count /= 2;
count--;
snd_sbdsp_command(chip, SB_DSP_BLOCK_SIZE);
snd_sbdsp_command(chip, count & 0xff);
@@ -553,6 +557,12 @@ static int snd_sb8_open(struct snd_pcm_s
}
snd_pcm_hw_constraint_ratnums(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
&hw_constraints_clock);
+ if (chip->dma8 > 3) {
+ snd_pcm_hw_constraint_step(runtime, 0,
+ SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 2);
+ snd_pcm_hw_constraint_step(runtime, 0,
+ SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 2);
+ }
return 0;
}
--
Rask Ingemann Lambertsen
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