[alsa-devel] aplay -l vs. aplay -L: Missing PCMs?

[Stephen Warren]

Jaroslav Kysela wrote:
> 
> On Fri, 20 Aug 2010, Stephen Warren wrote:
> 
> > Jaroslav Kysela wrote:
> >>
> >> On Fri, 20 Aug 2010, Stephen Warren wrote:
> >>
> >>> Jaroslav Kysela wrote:
> >>>>
> >>>> On Thu, 19 Aug 2010, Stephen Warren wrote:
> >>>>
> >>>>> The Azalia controller on NVIDIA GPUs gives 4 ALSA hw devices:
> >>>>>
> >>>>> (on card 1):
> >>>>>
> >>>>> [swarren at swarren-lx2 ~]$ sudo aplay -l
> >>>>> << includes hw=1,3 hw=1,7 hw=1,8 hw=1,9 >>
> >>>>> ... all of which appear to work OK.
> >>>>>
> >>>>> However, the list of available "PCMs" from aplay -L doesn't expose them all:
> >>>>>
> >>>>> [swarren at swarren-lx2 ~]$ sudo aplay -L
> >>>>> <<card 0 "Nvidia" elided>>
> >>>>> hdmi:CARD=NVidia_1
> >>>>>    HDA NVidia, NVIDIA HDMI
> >>>>>    HDMI Audio Output
> >>>>>
> >>>>> Instead, I imagined that I'd see 4 PCMs listed by "aplay -L"; one for each
> >>>>> converter. Is this an incorrect assumption? How would I make that happen?
> >>>>
> >>>> There is a bug in alsa-lib to namehint.c. The code assumes that hw device
> >>>> number is similar to logical device numbers which is not true in case of
> >>>> your HDMI devices:
> >>>>
> >>>> 3, 7, 8, 9
> >>>>
> >>>> The fallback code is used and only first logical device 0 is created.
> >>>>
> >>>> Could you test this patch?
> >>>>
> >>>> http://git.alsa-project.org/?p=alsa-
> lib.git;a=commitdiff;h=97d25c0766405453d3c298bd51dd4916121a4f6a
> >>>
> >>> I tested that, and unfortunately it doesn't seem to work; I get the exact same
> >>> aplay -L output.
> >>>
> >>> I debugged this a little, and see that add_card() is calculating the correct
> >>> max_devices value for card=1 str=hdmi. However, in the loop that right after
> >>> that calls try_config, when device=0, it returns 0, but when device=1, it
> >>> returns -2 (-ENOENT). This happens inside try_config where it calls
> >>> snd_config_search_definition (line 244 in latest git). At that point, buf is:
> >>>
> >>> hdmi:CARD=NVidia_1,DEV=1
> >>>
> >>> ... which seems reasonable.
> >>>
> >>> I'm a little confused about the device numbering though: The max_devices
> >>> value is counting values "3, 7, 8, 9" and hence gets 9. However, the
> >>> loop that calls try_config loops 0..max_devices-1, but bails out as soon
> >>> as any error is found, thus disallowing "holes" in the numbering. That
> >>> implies that "device" in that loop is a different numbering space? After
> >>> I noticed that, I hacked that loop to continue instead of break on
> >>> errors, and also removed the "err >= 0" condition from the loop,
> >>> expecting that when device==3/7/8/9, try_config might work. In fact, 0
> >>> still works (of course) and 1..8 all fail with err=-2, so I assume at
> >>> the same place in try_config.
> >>
> >> See my description. It's assumed that the logical devices
> >> (hdmi:DEV=<logical_device>) are continous. Does
> >> 'aplay -D hdmi:CARD=NVidia_1,DEV=1' work in your system?
> >
> > Sure, the logical device IDs should be contiguous. But then, I don't see why
> > the code would need to calculate max_devices (which is max HW device ID and
> > hence something other than logical device ID). Anyway...
> 
> There is no way to get the maximum logical device number at the moment.
> We can add some variables to the configuration files in future. The code
> just assumes that logical numbers does not go above the maximum hw device
> number.
> 
> > [swarren at swarren-lx2 ~]$ aplay -D hw:1,7 Shamisen-C4.wav
> > Playing WAVE 'Shamisen-C4.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
> >
> > [swarren at swarren-lx2 ~]$ aplay -D hdmi:CARD=NVidia_1,DEV=1
> > Shamisen-C4.wav ALSA lib confmisc.c:1286:(snd_func_refer) Unable to find
> > definition
> > 'cards.HDA-Intel.pcm.hdmi.1:CARD=NVidia_1,AES0=4,AES1=130,AES2=0,AES3=2'
> 
> Have you updated the HDA-Intel.conf file in the /usr/share/alsa/cards
> directory? There should be definition of:
> 
> HDA-Intel.pcm.hdmi.1 {
>          @args [ CARD AES0 AES1 AES2 AES3 ]
>          @args.CARD { type string }
>          @args.AES0 { type integer }
>          @args.AES1 { type integer }
>          @args.AES2 { type integer }
>          @args.AES3 { type integer }
>          @func refer
>          name {
> 
> ....
> 
> }

Ah, I has not installed the library, but was just pointing LD_LIBRARY_PATH at
alsa-lib/src/libs/. Once I ran "make install" and picked up that new config
file, "aplay -L" does list everything I expect it to.

Thanks very much.

> This addition is recent:
> 
> commit e6d5dcf1f625984605d362338d71162de45a6c60
> Author: Anssi Hannula <anssi.hannula at iki.fi>
> Date:   Tue Aug 3 20:27:49 2010 +0300
> 
>      HDA-Intel: present all 4 HDMI outputs instead of just the first one
> 
>      Commit 92608badc519a8c1f65d93743396517aaa582b53 in linux kernel added
>      the possibility of 3 additional HDMI devices on indexes 7-9.
> 
>      Present all those additional devices using the "hdmi" alias as well.
> 
>      Signed-off-by: Anssi Hannula <anssi.hannula at iki.fi>
>      Signed-off-by: Takashi Iwai <tiwai at suse.de>

-- 
nvpublic