trouble with dosemu and alsa oss emulation (and a fix for alsa)

trouble with dosemu and alsa oss emulation (and a fix for alsa)

[Vedran Rodic]

Hi. 

I'm having trouble with latest ALSA and oss emulation. I'm using dosemu to
play some DOS games and I've noticed that sound in DOS apps stops playing 
after short time (depending on the app). 


I'm regulary updating both alsa and dosemu, I suspected dosemu first, since
I had no problems whatsoever with alsa oss emulation. 

It turned out that this was not dosemu problem, but alsa oss emulation problem.
I've tracked it down to a change in  alsa-kernel/core/oss/pcm_oss.c. 
The change is here:
http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/alsa/alsa-kernel/core/oss/pcm_oss.c.diff?r1=1.40&r2=1.41

I'm currently using the latest pcm_oss.c but without this patch and it
works great again. 

I think that dosemu code - src/arch/linux/dosext/sound/linux_sound.c is
correct. 

Anyway, here's a couple of lines from dosemu sound log, starting arround 
where IOCTL error appears:

SB:[Linux] Get Free Fragments (16, 0)
SB:[Linux] Get Free Fragments (16, 0)
SB: Read 0x7f from DSP Write Buffer Status Register
SB: Going to write 128 bytes
SB:[Linux] Get Free Fragments (16, 0)
SB:[Linux] Get Free Fragments (16, 0)
SB: DSP command 0xd0 accepted
SB: Pausing DMA transfer, 256 bytes left
SB: Read 0x7e from DSP Write Buffer Status Register
SB: DSP command 0xd4 accepted
SB: Going to write 128 bytes
SB:[Linux] Get Free Fragments IOCTL error (Broken pipe)
SB:[Linux] Get Free Fragments IOCTL error (Broken pipe)
SB: Going to write 128 bytes
SB:[Linux] Get Free Fragments IOCTL error (Broken pipe)
SB:[Linux] Get Free Fragments IOCTL error (Broken pipe)
SB: Going to write 128 bytes


Vedran


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Re: trouble with dosemu and alsa oss emulation (and a fix for alsa)

[Ryan Underwood]

Hi,

On Sat, Sep 06, 2003 at 10:09:43PM +0200, Vedran Rodic wrote:
> Hi. 
> 
> I'm having trouble with latest ALSA and oss emulation. I'm using dosemu to
> play some DOS games and I've noticed that sound in DOS apps stops playing 
> after short time (depending on the app). 
> 
> 
> I'm regulary updating both alsa and dosemu, I suspected dosemu first, since
> I had no problems whatsoever with alsa oss emulation. 
> 
> It turned out that this was not dosemu problem, but alsa oss emulation problem.
> I've tracked it down to a change in  alsa-kernel/core/oss/pcm_oss.c. 
> The change is here:
> http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/alsa/alsa-kernel/core/oss/pcm_oss.c.diff?r1=1.40&r2=1.41
> 
> I'm currently using the latest pcm_oss.c but without this patch and it
> works great again. 
> 
> I think that dosemu code - src/arch/linux/dosext/sound/linux_sound.c is
> correct. 

Yeah, I know I tried dosemu with the ALSA OSS emulation before, and it
worked mostly correct (surprisingly enough!).  I'm glad you spotted this
regression, it might have gone overlooked for some time otherwise.

DOSEMU really needs the native ALSA sound output... one of these days ;)

-- 
Ryan Underwood, <nemesis at icequake.net>, icq=10317253

Re: trouble with dosemu and alsa oss emulation (and a fix for alsa)

[Jaroslav Kysela]

On Sat, 6 Sep 2003, Vedran Rodic wrote:

> Hi.
>
> I'm having trouble with latest ALSA and oss emulation. I'm using dosemu to
> play some DOS games and I've noticed that sound in DOS apps stops playing
> after short time (depending on the app).
>
>
> I'm regulary updating both alsa and dosemu, I suspected dosemu first, since
> I had no problems whatsoever with alsa oss emulation.
>
> It turned out that this was not dosemu problem, but alsa oss emulation problem.
> I've tracked it down to a change in  alsa-kernel/core/oss/pcm_oss.c.
> The change is here:
> http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/alsa/alsa-kernel/core/oss/pcm_oss.c.diff?r1=1.40&r2=1.41

Please, try patch bellow.

					Jaroslav


Index: pcm_oss.c
===================================================================
RCS file: /cvsroot/alsa/alsa-kernel/core/oss/pcm_oss.c,v
retrieving revision 1.47
diff -u -r1.47 pcm_oss.c
--- pcm_oss.c	3 Sep 2003 13:43:41 -0000	1.47
+++ pcm_oss.c	8 Sep 2003 07:12:58 -0000
@@ -1394,6 +1394,10 @@
 	}
 	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DELAY, &delay);
+		if (err == -EPIPE || err == -ESTRPIPE) {
+			err = 0;
+			delay = 0;
+		}
 	} else {
 		err = snd_pcm_oss_capture_position_fixup(substream, &delay);
 	}
@@ -1454,7 +1458,12 @@
 	} else {
 		if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 			err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DELAY, &avail);
-			avail = runtime->buffer_size - avail;
+			if (err == -EPIPE || err == -ESTRPIPE) {
+				avail = runtime->buffer_size;
+				err = 0;
+			} else {
+				avail = runtime->buffer_size - avail;
+			}
 		} else {
 			err = snd_pcm_oss_capture_position_fixup(substream, &avail);
 		}

-----
Jaroslav Kysela <perex@suse.cz>
Linux Kernel Sound Maintainer
ALSA Project, SuSE Labs


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Re: [Alsa-devel] trouble with dosemu and alsa oss emulation (and a fix for alsa)

[Vedran Rodic]

On Mon, Sep 08, 2003 at 09:14:40AM +0200, Jaroslav Kysela wrote:
> On Sat, 6 Sep 2003, Vedran Rodic wrote:
> 
> > Hi.
> >
> > I'm having trouble with latest ALSA and oss emulation. I'm using dosemu to
> > play some DOS games and I've noticed that sound in DOS apps stops playing
> > after short time (depending on the app).
> >
> >
> > I'm regulary updating both alsa and dosemu, I suspected dosemu first, since
> > I had no problems whatsoever with alsa oss emulation.
> >
> > It turned out that this was not dosemu problem, but alsa oss emulation problem.
> > I've tracked it down to a change in  alsa-kernel/core/oss/pcm_oss.c.
> > The change is here:
> > http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/alsa/alsa-kernel/core/oss/pcm_oss.c.diff?r1=1.40&r2=1.41
> 
> Please, try patch bellow.

It solved the problem. Thanks

Vedran