[alsa-devel] PC speaker beeps in 2.6.30?

Kurt J. Bosch kjb-temp-2006 at gmx.de
Tue Jun 30 13:31:07 CEST 2009

On 2009-06-30 07:57, Takashi Iwai wrote:
> At Mon, 29 Jun 2009 16:24:14 -0700,
> Paul Vojta wrote:
>> On Sun, Jun 28, 2009 at 01:09:26PM +0200, Kurt J. Bosch wrote:
>>> On 2009-06-28 10:38, Takashi Iwai wrote:
>>>> At Sat, 27 Jun 2009 23:39:08 -0700,
>>>> Paul Vojta wrote:
>>>>> On Sat, Jun 27, 2009 at 09:36:42AM +0200, Takashi Iwai wrote:
>>>>>> At Fri, 26 Jun 2009 10:03:54 +0400,
>>>>>> Michael Tokarev wrote:
>>>>>>> [Adding some more Cc's...]
>>>>>>> Am I the only concerned about this?  My 2.6.30 is still
>>>>>>> silent w.r.t. old good PC speaker beeps, and I wasn't
>>>>>>> able to make it to produce any sound.  Yes, as pointed
>>>>>>> out by others there is a control now, in alsa, and I
>>>>>>> can hear ugly and scary beeps from my stereo speakers
>>>>>>> (when they're turned on and when the control is un-muted).
>>>>>>> But that's.. not a solution/answer to the original
>>>>>>> question... ;)
>>>>>> Try 2.6.31-rc1.  There was a fix regarding beep frequency.
>>>>> Not necessarily.  Based on the OP's original post, as well as his mails
>>>>> to the LKML (Google the subject line to find them), he has a desktop
>>>>> system with external powered speakers connected to a sound card, and also
>>>>> a small PC speaker inside the system case.  He wants to hear the beeps
>>>>> coming out of the small speaker, since the external speakers (and/or sound
>>>>> card) are not always turned on.
>>>> To avoid someone misunderstanding: the beep routed through HD-audio
>>>> can also go to the built-in speaker.  It's just mixed up with the
>>>> normal audio output, and the volume is controlled via ALSA mixer
>>>> volume element.
>>>> But, once after it's hooked up to the codec, the beep can't be output
>>>> separately to the speaker.  It's always with other audio signal to the
>>>> same output target.
>>>> Or, on some systems (mostly laptops), the beep is hooked up to the
>>>> codec automatically no matter whether you set
>>>> CONFIG_SND_HDA_INPUT_BEEP once when the codec chip is initialized.
>>>> So, the behavior depends pretty much on the hardware implementation.
>>> I face the same problem as the OP since kernel 2.6.30 on ArchLinux on
>>> a desktop machine. I was able to get beep working through the built in
>>> speaker again by doing a 'modprobe -r pcspkr' followed by a
>>> 'modprobe pcspkr' after sysinit. It seems there is some kind of
>>> struggle goinig on here between alsa and pcspkr. Isn't there any
>>> kernel line or modules configuration option to disable the alsa pc-beep?
>> Hm... apparently not.  Probably there should be a module option for this, though.
> In the latest sound git tree, you can use "patch" file (passed via
> module option) to specify codec-specific setup.
> It's for 2.6.32, though.
Sounds rather complicated to me. :)
ALSA's snd-hda-intel is stealing the beeps allready 'owned' by pcspkr. 
It does
this every time it gets [re]loaded. Doing so while lacking a 
configuration option
to disable that behavior is a bug IMHO. (If you use beep to get some alarm
notification from hardware sensors or such you will depend on stereo 
connected and powered on.) Do I miss something ?

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