November 2007 - Alsa-devel - mailman.alsa-project.org

[alsa-devel] [PATCH] Use different buffer metrics in the PulseAudio plugin
by Lennart Poettering 26 Nov '07

26 Nov '07

Hi! Please commit this patch to alsa-plugins we ship in Fedora: http://cvs.fedoraproject.org/viewcvs/*checkout*/devel/alsa-plugins/1.0.14-b… It increases the "pre-buffering level" (i.e. start threshold) to the full buffer size minus one period. This makes PA work a little bit more like normal audio devices, and makes a few drop outs go away for software which uses very small period sizes. It also increases the initial maximum buffer size, which allows a small overcommit. That's not really an issue, but cleaner nonetheless so I smuggled it into this patch. Also reported in the ALSA BTS: https://bugtrack.alsa-project.org/alsa-bug/view.php?id=3578 Lennart -- Lennart Poettering Red Hat, Inc. lennart [at] poettering [dot] net ICQ# 11060553 http://0pointer.net/lennart/ GnuPG 0x1A015CC4

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[alsa-devel] If /dev/snd/controlCx EACCES vs. ENODEV mixup
by Lennart Poettering 26 Nov '07

26 Nov '07

Hi! If /dev/snd/controlC0 is not accessible due to a permission problem (EACCES), then alsa-libs will lie and return ENODEV. This is quite a bit confusing: <snip> $ sudo chmod 000 /dev/snd/controlC0 $ aplay -D hw:0 ALSA lib pcm_hw.c:1207:(_snd_pcm_hw_open) Invalid value for card aplay: main:546: audio open error: No such device </snip> (and strace shows that the actual problem is EACESS, as one would assume. I also filed this as bug on the BTS: https://bugtrack.alsa-project.org/alsa-bug/view.php?id=3600 BTW, what's the status of the BTS? Takashi asked me to post all my issues on the ML instead of on the BTS. So why have the BTS at all? It's even linked on the alsa-project.org front page under "I found a bug!", which is a bit misleading. If this Mantis thing is not liked at all, would it be possible to make some replacement available? Maybe just use the kernel bugzilla on bugzilla.kernel.org? It's very fast, and certainly more fun to work with than with Mantis. Lennart -- Lennart Poettering Red Hat, Inc. lennart [at] poettering [dot] net ICQ# 11060553 http://0pointer.net/lennart/ GnuPG 0x1A015CC4

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[alsa-devel] [PATCH] add support for Kore controller 2
by Daniel Mack 26 Nov '07

26 Nov '07

Added support for Native Instrument's Kore controller 2. This device has no audio but MIDI, input devices and ALSA controllers only. Signed-off-by: Daniel Mack <daniel(a)caiaq.de>

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[alsa-devel] [PATCH] soc/wm8731: Fix stereo mixer controls
by Ville Syrjälä 26 Nov '07

26 Nov '07

soc/wm8731: Fix stereo mixer controls Disable the simultaneous load feature for the line in and headphone out volume registers. This allows left and right volume levels to be controlled separately. Signed-off-by: Ville Syrjala <syrjala(a)sci.fi> --- diff --git a/sound/soc/codecs/wm8731.c b/sound/soc/codecs/wm8731.c index 7ca0b52..57fb95a 100644 --- a/sound/soc/codecs/wm8731.c +++ b/sound/soc/codecs/wm8731.c @@ -562,13 +562,13 @@ static int wm8731_init(struct snd_soc_device *socdev) /* set the update bits */ reg = wm8731_read_reg_cache(codec, WM8731_LOUT1V); - wm8731_write(codec, WM8731_LOUT1V, reg | 0x0100); + wm8731_write(codec, WM8731_LOUT1V, reg & ~0x0100); reg = wm8731_read_reg_cache(codec, WM8731_ROUT1V); - wm8731_write(codec, WM8731_ROUT1V, reg | 0x0100); + wm8731_write(codec, WM8731_ROUT1V, reg & ~0x0100); reg = wm8731_read_reg_cache(codec, WM8731_LINVOL); - wm8731_write(codec, WM8731_LINVOL, reg | 0x0100); + wm8731_write(codec, WM8731_LINVOL, reg & ~0x0100); reg = wm8731_read_reg_cache(codec, WM8731_RINVOL); - wm8731_write(codec, WM8731_RINVOL, reg | 0x0100); + wm8731_write(codec, WM8731_RINVOL, reg & ~0x0100); wm8731_add_controls(codec); wm8731_add_widgets(codec); -- Ville Syrjälä syrjala(a)sci.fi http://www.sci.fi/~syrjala/

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[alsa-devel] Audigy LS driver
by Daniel Sabo 26 Nov '07

26 Nov '07

Hi, I'm interested in helping with the ca0106 driver. My understanding is that the dmix and multi plugins can't be used with each other, which means that right now it not possible to have a dmixed surround sound device with this card. The driver has 4 stereo devices on it (one for each DSP on the board?), would it be possible for me to merge devices 0,1, and 2 into a single 6 channel device? I have some experience with driver development doing ARM SoC stuff, but this is my first time messing with a linux driver. Thanks, - Daniel Sabo

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[alsa-devel] Semantics of a single period per buffer?
by Dave Dillow 25 Nov '07

25 Nov '07

While refining the sis7019 for submission, I found a possible issue with having a single period per buffer. The easy way out is to set the minimum number of periods to 2, but I see other drivers allow a single period. This leads to a question about the semantics of a single period that I've not been able to resolve using Google. Any one have any thoughts or pointers to a discussion on having a single period per buffer? Should it be a one-shot play, or just let it hit XRUN every time? Other ideas? Thanks, Dave

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[alsa-devel] Inappropriate ioctl for device on alsalib with uclibc and arm platform
by Federico Fuga 23 Nov '07

23 Nov '07

Hi, Maybe I am a little bit off-topic here, but I think this question may be related with a bug (maybe not in the alsa library, but I am a little confused now), so I apologize in advance. I am building a uclibc-based system on arm board. I have compiled the library 1.0.14a with uClibc 0.9.29 and kernel 2.6.23.1 / kernel headers 2.6.22. Settings the config params of mixer with "alsactl restore" fails with an "inappropriate ioctl for device" error: # alsactl restore alsactl: set_control:1159: Cannot write control '2:0:0:Speaker Playback Volume:0' : Inappropriate ioctl for device while traceing with strace I see that: open("/usr/lib/libasound.so.2", O_RDONLY) = 4 fstat(4, {st_mode=S_IFREG|0755, st_size=716844, ...}) = 0 close(4) = 0 open("/dev/snd/controlC0", O_RDONLY) = 4 close(4) = 0 open("/dev/snd/controlC0", O_RDWR) = 4 ioctl(4, USBDEVFS_CONTROL, 0xbeab09ec) = 0 ioctl(4, UI_DEV_CREATE, 0xbeab0ad0) = 0 ioctl(4, USBDEVFS_CONNECTINFO, 0xbeab0654) = 0 ioctl(4, USBDEVFS_HUB_PORTINFO, 0xbeab0768) = -1 ENOTTY (Inappropriate ioctl for device) write(2, "alsactl", 7alsactl) = 7 but aplay see all the board and seems to work properly: # aplay -l **** List of PLAYBACK Hardware Devices **** card 0: EMX270 [EM-X270], device 0: AC97 HiFi AC97 HiFi-AC97-0 [] Subdevices: 1/1 Subdevice #0: subdevice #0 card 0: EMX270 [EM-X270], device 1: AC97 Aux AC97 Aux-AC97-1 [] Subdevices: 1/1 Subdevice #0: subdevice #0 # aplay -L default:CARD=EMX270 EM-X270, Default Audio Device null Discard all samples (playback) or generate zero samples (capture) # speaker-test speaker-test 1.0.14 Playback device is default Stream parameters are 48000Hz, S16_LE, 1 channels Using 16 octaves of pink noise Rate set to 48000Hz (requested 48000Hz) Buffer size range from 8 to 32768 Period size range from 8 to 2040 Using max buffer size 32768 Periods = 4 was set period_size = 1024 was set buffer_size = 32768 0 - Front Left Time per period = 2.528627 0 - Front Left Time per period = 2.999174 But I hear no sound (the levels are all off). In a similar installation based on glibc (Armstrong linux) with the same version of kernel, alsa and all other stuff works correctly. root@em-x270:~$ cat /proc/asound/devices 0: [ 0] : control 16: [ 0- 0]: digital audio playback 17: [ 0- 1]: digital audio playback 24: [ 0- 0]: digital audio capture 33: : timer The device nodes in /dev/sound are created by udev, and major/minor codes and permissions seems ok. Can you give me some hint on how to solve this issue? Thank you in advance ing. Federico Fuga

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[alsa-devel] How to cont the sound cards?
by Cosmin Humeniuc 23 Nov '07

23 Nov '07

Hi, I am trying to develop an application using the ALSA library. I read in a book about the snd_cards function, but it doesn't seem to be defined anywhere. (The book is rather old, though, it talks about the 0.5.x series). The compiler doesn't complain, but the linker gives me an "undefined reference to `snd_cards'" error. I assume this function is deprecated, but what can I use instead? Cosmin

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[alsa-devel] Lock free ring buffers and SMP safety
by Matt Bucknall 23 Nov '07

23 Nov '07

Hello, Yes, this old chestnut. I've spent the best part of today trying to ascertain whether or not, in practical terms, a single-producer, single-consumer lock free ring-buffer can be written purely in C/C++ and be SMP safe on multiple architectures without memory barriers. Information I've found has been largely conflicting so I've given up trying to get a conclusive answer. Instead I'll just go with the flow. What is the general consensus amongst ALSA application developers when it comes to implementing this kind of buffer? Is it possible to use memory barriers through some user space API call that I don't know about? Thanks in advance for any comments/suggestions. Matt.

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Re: [alsa-devel] Mbox II DigiDisign
by Clemens Ladisch 23 Nov '07

23 Nov '07

rmgls(a)free.fr wrote: > on jeudi 22 novembre 2007 Clemens Ladisch" <cladisch(a)fastmail.net wrote: > >> aplay plays nothing and reports: (alsa-lib pcm error). > > > What exactly does it report? > > it reports > > segfault! Does this also happen when you run "aplay -D plughw coq.wav"? > Program received signal SIGSEGV, Segmentation fault. > [Switching to Thread 0xb7cfb6b0 (LWP 21167)] > 0xb7f0389c in ?? () from /usr/lib/libasound.so.2 > (gdb) bt > #0 0xb7f0389c in ?? () from /usr/lib/libasound.so.2 > #1 0x00038007 in ?? () > ... > > if needed i'll build a non stripped aplay. That would be helpful. Regards, Clemens

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