Re: [LAU] make alsa device hw:1,0 be hw:0,0 somehow

This can be hard to do. Why can't you tell software to use hw:1 ?

Most system BIOS setup utilities can be used to disable onboard sound.
Getting Linux to reorder them is also possible but can be complex
depending on the types of devices (PCI, USB etc)

On Sun, Oct 4, 2015 at 2:57 PM, ansible <bburdette@email-addr-hidden> wrote:
> I compiled supercollider to play through portaudio rather than jack, as it
> usually does, in an attempt to reduce latency and hassle. It works for
> audio device hw:0,0, but it doesn't work for hw:1,0. My problem is that on
> my device hw:0,0 has horrible latency - 70ms - while hw:1,0 has 9ms latency,
> much better.
>
> So what I'd like to do is reorder the audio devices, or disable the onboard
> audio, and have my current hw:1,0 be the hw:0,0 device. Hopefully then
> supercollider will work with it and I'll have those coveted low latency
> numbers. This is on arch linux on a bananapi armv7 computer.
>
> So here's the output from aplay -l:
>
> ```
> [bananapi@email-addr-hidden ~]$ aplay -l
> **** List of PLAYBACK Hardware Devices ****
> card 0: sunxicodec [sunxi-CODEC], device 0: M1 PCM [sunxi PCM]
> Subdevices: 1/1
> Subdevice #0: subdevice #0
> card 1: Pro [Sound Blaster X-Fi Go! Pro], device 0: USB Audio [USB Audio]
> Subdevices: 1/1
> Subdevice #0: subdevice #0
> [bananapi@email-addr-hidden ~]$
> ```
>
> According to the [alsa wiki][1], I should be able to reorder the devices
> using a .conf file. See 'set the default sound card'. It gives the example
> of this:
>
> ```
> /etc/modprobe.d/alsa-base.conf
>
> options snd_mia index=0
> options snd_hda_intel index=1
> ```
>
> Ok so I made a file like that, but I only know the name of the usb driver,
> not the onboard sound driver. lsmod reveals the following:
>
> ```
> [bananapi@email-addr-hidden ~]$ lsmod
> Module Size Used by
> snd_usb_audio 96225 0
> snd_hwdep 5757 1 snd_usb_audio
> snd_usbmidi_lib 18033 1 snd_usb_audio
> cdc_acm 20518 0
> spidev 6217 0
> spi_sun7i 17802 0
> sunxi_cedar_mod 9808 0
> mali_drm 2608 0
> drm 209226 1 mali_drm
> mali 111427 0
> disp_ump 861 0
> ump 52415 2 mali,disp_ump
> ap6210 584133 0
> ip_tables 12937 0
> x_tables 17443 1 ip_tables
> ```
>
> If I do "modprobe -r snd_usb_audio", then snd_hwdep and snd_usbmidi_lib both
> disappear too, so they are all for the same device I think. That leaves
> nothing for the driver name for the onboard audio.
>
> The alsa wiki says that the driver names should be in "cat
> /proc/asound/modules" but I don't have that directory on my system.
>
> So anyway I made an alsa-base.conf file as directed, which looks like this:
>
> ```
> [bananapi@email-addr-hidden ~]$ cat /etc/modprobe.d/alsa-base.conf
> options snd_usb_audio index=0
> options sunxicodec index=1
> [bananapi@email-addr-hidden ~]$
> ```
>
> After creating that file and rebooting aplay just returns this.
>
> ```
> [bananapi@email-addr-hidden ~]$ aplay -l
> **** List of PLAYBACK Hardware Devices ****
> card 0: sunxicodec [sunxi-CODEC], device 0: M1 PCM [sunxi PCM]
> Subdevices: 1/1
> Subdevice #0: subdevice #0
> [bananapi@email-addr-hidden ~]$
> ```
>
> So this alsa-base.conf has the effect of making only the onboard audio
> available instead of reordering. I most likely have the 'sunxicodec' name
> wrong for the onboard audio, I'm just guessing at that, and have no idea
> what the driver name for that is, if there even is one. I'm kind of
> suspecting the audio device is part of a monolithic driver for the whole
> system-on-chip, is that possible?
>
> [1]:
> https://wiki.archlinux.org/index.php/Advanced_Linux_Sound_Architecture
>
>
>
> --
> View this message in context: http://linux-audio.4202.n7.nabble.com/make-alsa-device-hw-1-0-be-hw-0-0-somehow-tp97402.html
> Sent from the linux-audio-user mailing list archive at Nabble.com.
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Received on Mon Oct 5 04:15:02 2015