[alsa-devel] amixer shows capability "penum" on every Simple mixer control

[Takashi Iwai]

At Tue, 13 Mar 2012 10:52:21 +0100,
Takashi Iwai wrote:
> 
> At Mon, 12 Mar 2012 22:09:35 +0100,
> Christian Esken (KDE) wrote:
> > 
> >  Hello,
> > 
> >  when I run amixer it shows the capability "penum" on nearly every 
> >  Simple mixer control.
> >  I posted the bug report 
> >  https://bugtrack.alsa-project.org/alsa-bug/view.php?id=5496 , but 
> >  Raymond asked me to report it on this mailing list ("as it is related to 
> >  this patch 6d511eefa05878abee9f8b9145697230de605200 Implements support 
> >  for capture/playback enums.").
> > 
> >  I posted  details for the following two examples in 
> >  https://bugtrack.alsa-project.org/alsa-bug/view.php?id=5496 :
> > 
> >  1) "Creative X-Fi" does not have any Enum's. alsamixer does not show 
> >  Enums's. amixer lists "penum" for ALL Simple mixer controls.
> > 
> >  2) "HDA ATI SB" has no penum's, only 3 cenum's. alsamixer shows it 
> >  correctly, but amixer disagrees and shows penum for NEARLY ALL Simple 
> >  mixer controls (except for those with cpability "cenum").
> > 
> > 
> >  I found this as I received several bug reports for KMix with "absurd" 
> >  amixer output. I could perceive from those bug report that the bug is 
> >  affecting a lot (or all?) sound cards.
> 
> Looks like a bug in alsa mixer abstraction, indeed.
> Will take a look at it later.

I committed the fix to git tree now.  The fix patch is below.


Takashi

---
From: Takashi Iwai <tiwai at suse.de>
Subject: [PATCH] mixer: Remove redundant CHECK_ENUM() from snd_mixer_selem_is_enum*()

The functions to check whether the element is an enum don't need the
extra check of the type.  It should return simply 0 or 1 without error.

Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 src/mixer/simple.c |    2 --
 1 file changed, 2 deletions(-)

diff --git a/src/mixer/simple.c b/src/mixer/simple.c
index 8079fe7..ec22a9c 100644
--- a/src/mixer/simple.c
+++ b/src/mixer/simple.c
@@ -889,7 +889,6 @@ int snd_mixer_selem_is_enumerated(snd_mixer_elem_t *elem)
 int snd_mixer_selem_is_enum_playback(snd_mixer_elem_t *elem)
 {
 	CHECK_BASIC(elem);
-	CHECK_ENUM(elem);
 	return sm_selem_ops(elem)->is(elem, SM_PLAY, SM_OPS_IS_ENUMERATED, 1);
 }
 
@@ -901,7 +900,6 @@ int snd_mixer_selem_is_enum_playback(snd_mixer_elem_t *elem)
 int snd_mixer_selem_is_enum_capture(snd_mixer_elem_t *elem)
 {
 	CHECK_BASIC(elem);
-	CHECK_ENUM(elem);
 	return sm_selem_ops(elem)->is(elem, SM_CAPT, SM_OPS_IS_ENUMERATED, 1);
 }
 
-- 
1.7.9.2