[alsa-devel] multi-channel playback regression

[Takashi Iwai]

At Thu, 23 Jul 2009 13:29:21 +0200,
I wrote:
> 
> At Thu, 23 Jul 2009 10:39:04 +0200 (CEST),
> Jaroslav Kysela wrote:
> > 
> > On Thu, 23 Jul 2009, Takashi Iwai wrote:
> > 
> > > At Thu, 23 Jul 2009 10:14:27 +0200 (CEST),
> > > Jaroslav Kysela wrote:
> > >>
> > >> On Thu, 23 Jul 2009, Wu Fengguang wrote:
> > >>
> > >>>> Is this with the patched (as is on sound git tree) kernel?
> > >>>
> > >>> Yes, it's unmodified latest git tree.
> > >>>
> > >>>> What if changing from #if 1 to #if 0?
> > >>>
> > >>> This makes 8-channel playback work again.
> > >>
> > >> Can we check if we running under VMWare at runtime?
> > >
> > > No idea.  But, an option to allow to choose manually might be usefl
> > > for other broken hardwares that require a similar fallback like
> > > VMware, although this doesn't conflict with the automatic detection
> > > of vmware.
> > 
> > Yes, maybe a sysfs attribute might be useful.
> 
> How about the patch below?
> This is in sound-unstable tree fix/pcm-hwptr-debug branch.

And VMware check patch is below.
Note that it's totally untested and I'm really not sure whether this
works...

This patch is also on fix/pcm-hwptr-debug branch of sound-unstable
tree.


thanks,

Takashi

===
From f5a9b7ddd3bd3db496f93ef2a4f1b95531d28a51 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai at suse.de>
Date: Thu, 23 Jul 2009 13:24:49 +0200
Subject: [PATCH] ALSA: pcm - Add VMware workaround

Enable the VMware workaround again by checking boot_cpu_data
x86_hyper_vendor field.

Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/core/pcm.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 15502af..a637dc4 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -28,6 +28,10 @@
 #include <sound/pcm.h>
 #include <sound/control.h>
 #include <sound/info.h>
+/* for VMware check */
+#ifdef CONFIG_X86
+#include <asm/processor.h>
+#endif
 
 MODULE_AUTHOR("Jaroslav Kysela <perex at perex.cz>, Abramo Bagnara <abramo at alsa-project.org>");
 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
@@ -730,6 +734,11 @@ int snd_pcm_new(struct snd_card *card, const char *id, int device,
 		snd_pcm_free(pcm);
 		return err;
 	}
+#ifdef CONFIG_X86
+	/* workaround for VMware */
+	if (boot_cpu_data.x86_hyper_vendor == X86_HYPER_VENDOR_VMWARE)
+		pcm->filter_bogus_irq = 1;
+#endif
 	if (rpcm)
 		*rpcm = pcm;
 	return 0;
-- 
1.6.3.3