Arch Linux

Bednar

Member

Registered: 2015-09-19

Posts: 73

CONFIG_SND_HDA_PREALLOC_SIZE is set to 0 in the kernel config (5.17.1)

See: https://bugs.archlinux.org/task/68092

Any chance we could update the config to 2048?

https://github.com/archlinux/svntogit-p … nfig#L6764

Slithery

Administrator

From: Norfolk, UK

Registered: 2013-12-01

Posts: 5,776

Re: CONFIG_SND_HDA_PREALLOC_SIZE is set to 0 in the kernel config (5.17.1)

You'd be better off adding to the bug report. The Arch developers rarely (if ever) visit the forums.

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Bednar

Member

Registered: 2015-09-19

Posts: 73

Re: CONFIG_SND_HDA_PREALLOC_SIZE is set to 0 in the kernel config (5.17.1)

thanks, I did just that.

schard

Forum Moderator

From: Hannover

Registered: 2016-05-06

Posts: 2,648

Website

Re: CONFIG_SND_HDA_PREALLOC_SIZE is set to 0 in the kernel config (5.17.1)

According to the git blame it was reset to 0 deliberately:
https://github.com/archlinux/svntogit-p … 7012eeddd8
https://bugs.archlinux.org/task/70064

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Bednar

Member

Registered: 2015-09-19

Posts: 73

Re: CONFIG_SND_HDA_PREALLOC_SIZE is set to 0 in the kernel config (5.17.1)

According to the git blame it was reset to 0 deliberately:
https://github.com/archlinux/svntogit-p … 7012eeddd8
https://bugs.archlinux.org/task/70064

Unfortunately, 0 is causing issues still: https://gitlab.freedesktop.org/pipewire … ssues/2272

In my case I have audio disappearing after a period of inactivity or when waking up from sleep.

The solution is to either recompile the kernel or use below:

echo 2048 | sudo tee /proc/asound/card*/pcm*/sub*/prealloc

Bednar

Member

Registered: 2015-09-19

Posts: 73

Re: CONFIG_SND_HDA_PREALLOC_SIZE is set to 0 in the kernel config (5.17.1)

BTW, Fedora seems to be using 2048:

https://gitlab.com/cki-project/kernel-a … ALLOC_SIZE

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,209

Re: CONFIG_SND_HDA_PREALLOC_SIZE is set to 0 in the kernel config (5.17.1)

Not for x86: https://gitlab.com/cki-project/kernel-a … ALLOC_SIZE and as mentioned in the discussion/bug reports there can be actual issues if the value is set "too high" as well.

Maybe this really is something where people need to override this themselves on an as needed basis.

latalante1

Member

Registered: 2018-08-30

Posts: 111

Re: CONFIG_SND_HDA_PREALLOC_SIZE is set to 0 in the kernel config (5.17.1)

For Fedora, it is 0.
https://src.fedoraproject.org/rpms/kern … onfig#_599
It is 0 for most kernel configurations.

CONFIG_SND_HDA_PREALLOC_SIZE=0

is automatically set.

include/generated/autoconf.h
include/config/auto.conf

You cannot modify it (including and through in menuconfig). Except for the configuration

if !SND_DMA_SGBUF

then you can set the range value

0 32768

.
https://git.kernel.org/pub/scm/linux/ke … 5.17.y#n26

Last edited by latalante1 (2022-04-06 09:57:55)

Bednar

Member

Registered: 2015-09-19

Posts: 73

Re: CONFIG_SND_HDA_PREALLOC_SIZE is set to 0 in the kernel config (5.17.1)

well, I guess it really will need to be overridden on a case by case basis. In my case I have to do it otherwise I have unusable audio.

I will try to investigate this more and possibly report upstream.

smartding

Member

Registered: 2021-02-21

Posts: 35

Re: CONFIG_SND_HDA_PREALLOC_SIZE is set to 0 in the kernel config (5.17.1)

The help text for the kernel config CONFIG_SND_HDA_PREALLOC_SIZE says:

Specifies the default pre-allocated buffer-size in kB for the HD-audio driver. A larger buffer (e.g. 2048) is preferred for systems using PulseAudio. The default 64 is chosen just for compatibility reasons. On x86 systems, the default is zero as we need no preallocation.

Note that the pre-allocation size can be changed dynamically via a proc file (/proc/asound/card*/pcm*/sub*/prealloc), too.

So it's zero as we need no preallocation on X86 systems.