Date: Thu, 16 Jan 2003 19:15:49 -0500 (EST) From: Marat Fayzullin <fms@cs.umd.edu> To: <freebsd-hackers@freebsd.org> Subject: Maestro2E Problem (pcm bug?) Message-ID: <Pine.SOL.4.33.0301161914300.9600-100000@ringding.cs.umd.edu>
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Hello!
I have found that Maestro2E refuses to produce sound if the total
buffer size is <16kB. For example, look at the following program:
int main(int argc,char *argv)
{
int I,J,K,SoundFD;
char Buf[256];
SoundFD=open("/dev/dsp",O_WRONLY);
if(SoundFD<0) return(1);
J=AFMT_U8;
ioctl(SoundFD,SNDCTL_DSP_SETFMT,&J);
J=0;
ioctl(SoundFD,SNDCTL_DSP_STEREO,&J);
J=44100;
ioctl(SoundFD,SNDCTL_DSP_SPEED,&J);
J=11|(8<<16); // <------- 8x2048 buffers
ioctl(SoundFD,SNDCTL_DSP_SETFRAGMENT,&J);
for(J=0;J<256;J++) Buf[J]=J&1? 0:127;
for(J=0;J<10000;J++) write(SoundFD,Buf,256);
close(SoundFD);
return(0);
}
When I set the fragmentation to 64x256 or 8x2048 or some other similar
value, I get the sound. Otherwise, the driver reports "channel dead"
and there is silence. My suspicion is that the DMA buffer has to be
allocated at a 16kB segment boundary, which does not always happen when
its size is <16kB. Unfortunately, I do not know FreeBSD kernel well enough
to verify and fix this problem.
Could somebody with enough expertise please look at it and try fixing
the problem? Because of this, I can't test several programs planned for
release.
System specifications:
SYSTEM: FreeBSD 4.6.2-RELEASE
MACHINE: Toshiba Portege 3380
SOUND: ESS Maestro2E
PS: Posted this to "mobile" and "multimedia" lists some time ago with
no success.
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