Re: [Emu10k1-devel] Problems with poll/select

[Rui S. <rui...@cl...>]

On Mon, 25 Feb 2002, Shane Wegner wrote:

We don't start recording automatically on select() anymore.
You must use SNDCTL_DSP_SETTRIGGER to start the recording.
In your example bellow this would be done just before
the while(1) loop.

Rui

P.S: The "read select() starts recording" was also removed
from latest OSS spec.

> Hi all,
> 
> I have been working on moving from the ALSA drivers to the
> latest emu10k1 OSS CVS drivers for the advanced routing
> controls.  Mostly, the upgrade has gone smoothly, however,
> I am the author of an audio application which breaks under
> the emu10k1 driver.
> 
> Basically what seems to be happening is the select or poll
> system calls aren't returning during audio capture so my
> application doesn't bother to read audio data.  I have
> enclosed a tiny test program to demonstrate this.  Under
> ALSA or an OSS driver for another audio card, there is all
> kinds of output; with emu10k1, it is quite silent.
> 
> I have tested both the latest drivers in CVS at sourceforge
> as well as those in the 2.4.18-rc4 kernel prepatch.  If
> anyone has any suggestions, I would appreciate hearing from
> you?  I glanced at audio.c where the poll function lives
> but can't make sense of it at this point.
> 
> --- begin test program ---
> #include <stdio.h>
> #include <sys/types.h>
> #include <sys/stat.h>
> #include <fcntl.h>
> 
> int main()
> {
> fd_set rs;
> char buff[1024];
> int fd, i;
> if ((fd = open("/dev/dsp", O_RDONLY)) == -1)
> abort("open failed.");
> while (1) {
> FD_ZERO(&rs);
> FD_SET(fd, &rs);
> if ((i = select(fd + 1, &rs, NULL, NULL, NULL)) <= 0)
> continue;
> i = read(fd, buff, 1024);
> printf("Got %d bytes.\n", i);
> }
> return 0;
> }
> --- end test program ---
> 
>