Arch Linux

Sir Ferdek

Member

From: Poland

Registered: 2010-08-19

Posts: 7

[SOLVED] Speakers "POPS" on shutdown/reboot

Last week I bought the Acer Aspire 5740G laptop. And here I am, installing Arch Linux x64 on it. Almost everything works fine except a major bug related with sound card. The chipset itself is well supported by default Arch installation, but strange thing happen when I try to reboot or shut it down.

Just before the computer turns off and after archie prints "REBOOTING" (or "Shuting down") I hear very loud POP from speakers (it sounds like some kind of capacitor discharge). I'm afraid in the near future archie will blow up my laptop's speakers (yes, it is very very LOUD!).

Today I lost six hours trying to find some information on the Internet about how to solve it. Unfortunately, despite many similar bug reports on ubuntu's forum concerning different hardware (hp laptops for instance), it is still unanswered what is causing the problem.

To my mind, forcing the sound card to shutdown BEFORE other hardware would solve the problem, but since I am not familiar with this kind of linux-black-magic-knowledge I beg you guys to help me solve it out. Or I will be forced to stop using Arch linux.

IMPORTANT! There is no pop from speakers when using Linpus Linux shipped with Acer, Arch Linux livecd or Windows...

PS. It was difficult to choose the right section of forum (Laptop related issues or kernel/hardware? ). If I'm wrong, move this topic

Want some lspci? Wait till I switch back to speaker's killing Archie

EDIT:
Alsamixer shows:

Card: HDA Intel
Chipset: Realtek ALC272X

And LSPCI:

Uploaded with ImageShack.us

Last edited by Sir Ferdek (2010-08-19 19:21:46)

skanky

Member

From: WAIS

Registered: 2009-10-23

Posts: 1,847

Re: [SOLVED] Speakers "POPS" on shutdown/reboot

These two threads may give a starting point (see also the links in them):
https://bbs.archlinux.org/viewtopic.php?id=92920
https://bbs.archlinux.org/viewtopic.php?id=93336

---

"...one cannot be angry when one looks at a penguin."  - John Ruskin
"Life in general is a bit shit, and so too is the internet. And that's all there is." - scepticisle

brebs

Member

Registered: 2007-04-03

Posts: 3,742

Re: [SOLVED] Speakers "POPS" on shutdown/reboot

I had this with a Dell laptop - the solution was to use amixer to mute the speakers during shutdown.

Sir Ferdek

Member

From: Poland

Registered: 2010-08-19

Posts: 7

Re: [SOLVED] Speakers "POPS" on shutdown/reboot

Thanks for your fast responses.
Blacklisting pcskp or snd_pcsp doesn't work.
Additional options in modprobe.conf (options snd-hda-intel power_save=0 model=laptop/acer-aspire/eeepc-p901) also don't work.

Rebooting now to try brebs' method...

Sir Ferdek

Member

From: Poland

Registered: 2010-08-19

Posts: 7

Re: [SOLVED] Speakers "POPS" on shutdown/reboot

It looks like problem solved But no, brebs' suggestion doesn't work...

Just before rebooting I had a "stupid" idea of manually removing the snd-hda-intel module before rebooting, but it seemed to me to have the same effect like muting.
And just out of curiosity, after another failure, I've typed

modprobe -r snd-hda-intel
reboot

and it went flawlessly...

Anyway, alsa daemon wanted to store the mixer settings and didn't find audio card. Will modprobe and alsa daemon work properly if I put it in the rc.shutdown file? (or sth like that). What will be run first, the rc.shutdown or daemons unloading?

brebs

Member

Registered: 2007-04-03

Posts: 3,742

Re: [SOLVED] Speakers "POPS" on shutdown/reboot

Edit the alsa script to modprobe -r, *after* the alsactl store.

Sir Ferdek

Member

From: Poland

Registered: 2010-08-19

Posts: 7

Re: [SOLVED] Speakers "POPS" on shutdown/reboot

Great idea brebs.

That left almost all my questions answered.
Should I update some wiki's in order to help others or just add a Solved tag in the topic?

---UPDATE---
Seems like removing snd-hda-intel is lowering the noise by 75%, to completly mute it one must mute the master channel in alsamixer.
@Brebs - do you know the way in which this could be done automagically (another fix in alsa script should do the work, I just dunno what to paste there )

---UPDATE---

After a bit of research, found a solution.

# nano /etc/rc.d/alsa

Find a line which looks like:

alsactl store [...]

and just after it paste this fix

amixer set Master mute >/dev/null
modprobe -r snd-hda-intel

Voilà! That's all Hope that helped somebody.

Last edited by Sir Ferdek (2010-08-19 19:21:10)