On 21/01/2008, Takashi Iwai tiwai@suse.de wrote:

At Sun, 20 Jan 2008 21:31:33 +0000, Adrian McMenamin wrote:

...

I am still trying to find out what is wrong with my sound driver - for the Sega Dreamcast (sound/sh/aica.c). This works perfectly with the OSS emulation layer but will not work with the ALSA layer per se.

As this shows - there is something wrong with how it interacts with the PCM layer of alsa-lib:

$ aplay -l **** List of PLAYBACK Hardware Devices **** card 0: AICA [AICA], device 0: AICA PCM [AICA PCM] Subdevices: 1/1 Subdevice #0: subdevice #0 $ $ $ aplay -L null Discard all samples (playback) or generate zero samples (capture)

I have no reason to think that my build of alsa-lib is wrong - both the automagic buildroot build and my own by-hand build behave the same way.

So therefore I assume it must be something in the driver?!

I don't think so. Try to load snd-dummy.

OK, I went one better than that. I switched to a Debian based distribution and installed alsa via apt-get (something of a struggle with just 16MB to play with, but it can be done).

But while it seems better, it is still not fully functioning:

supercat:/usr/share/sounds/alsa# aplay -l **** List of PLAYBACK Hardware Devices **** card 0: AICA [AICA], device 0: AICA PCM [AICA PCM] Subdevices: 1/1 Subdevice #0: subdevice #0

supercat:/usr/share/sounds/alsa# aplay -L PCM list: hw { @args.0 CARD @args.1 DEV @args.2 SUBDEV @args.CARD { type string default { @func getenv vars { 0 ALSA_PCM_CARD 1 ALSA_CARD } default { @func refer name 'defaults.pcm.card' } } } @args.DEV { type integer default { @func igetenv vars { 0 ALSA_PCM_DEVICE } default { @func refer name 'defaults.pcm.device' } } } @args.SUBDEV { type integer default { @func refer name 'defaults.pcm.subdevice' } } type hw card $CARD device $DEV subdevice $SUBDEV } plughw { @args.0 CARD @args.1 DEV @args.2 SUBDEV @args.CARD { type string default { @func getenv vars { 0 ALSA_PCM_CARD 1 ALSA_CARD } default { @func refer name 'defaults.pcm.card' } } } @args.DEV { type integer default { @func igetenv vars { 0 ALSA_PCM_DEVICE } default { @func refer name 'defaults.pcm.device' } } } @args.SUBDEV { type integer default { @func refer name 'defaults.pcm.subdevice' } } type plug slave.pcm { type hw card $CARD device $DEV subdevice $SUBDEV } } plug { @args.0 SLAVE @args.SLAVE { type string } type plug slave.pcm $SLAVE } shm { @args.0 SOCKET @args.1 PCM @args.SOCKET { type string } @args.PCM { type string } type shm server $SOCKET pcm $PCM } tee { @args.0 SLAVE @args.1 FILE @args.2 FORMAT @args.SLAVE { type string } @args.FILE { type string } @args.FORMAT { type string default raw } type file slave.pcm $SLAVE file $FILE format $FORMAT } file { @args.0 FILE @args.1 FORMAT @args.FILE { type string } @args.FORMAT { type string default raw } type file slave.pcm null file $FILE format $FORMAT } null { type null } cards 'cards.pcm' front 'cards.pcm.front' rear 'cards.pcm.rear' center_lfe 'cards.pcm.center_lfe' side 'cards.pcm.side' surround40 'cards.pcm.surround40' surround41 'cards.pcm.surround41' surround50 'cards.pcm.surround50' surround51 'cards.pcm.surround51' surround71 'cards.pcm.surround71' iec958 'cards.pcm.iec958' spdif 'cards.pcm.iec958' modem 'cards.pcm.modem' phoneline 'cards.pcm.phoneline' default 'cards.pcm.default' dmix 'cards.pcm.dmix' dsnoop 'cards.pcm.dsnoop'

Below seems fair enough...

supercat:/usr/share/sounds/alsa# aplay Noise.wav Playing WAVE 'Noise.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono ALSA lib pcm_plug.c:773:(snd_pcm_plug_hw_refine_schange) Unable to find an usable access for 'default' aplay: set_params:899: Access type not available

But this isn't...

supercat:/usr/share/sounds/alsa# aplay -D plughw:0,0 Noise.wav Playing WAVE 'Noise.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono ALSA lib pcm_plug.c:773:(snd_pcm_plug_hw_refine_schange) Unable to find an usable access for 'plughw:0,0' aplay: set_params:899: Access type not available

Any clues?

(Just to be clear:

supercat:/usr/share/sounds/alsa# modprobe snd-pcm-oss supercat:/usr/share/sounds/alsa# cat Noise.wav > /dev/dsp

works as one would expect)