[alsa-devel] Speaker burnout

[David Henningsson]

On 2015-04-07 09:49, Eliot Blennerhassett wrote:
> On 07/04/15 19:26, Clemens Ladisch wrote:
>
>> In theory, it would be possible to do the mixing in the analog domain.
>> But there is no way to find out what the HDA codec actually does except
>> trying it out.
>
>
> Dear testers, please perform the following steps:
>
> 1. Place laptop on heat-resistant surface in a well-ventilated space.
> Have a fire extinguisher handy.  Put on your earmuffs.
> 2. Start stopwatch
> 3. Set all alsa volumes to maximum
> 3.1 If screaming noise not already evident, play this full-scale square wave
> 4.1 If smoke or flames appear from your laptop, stop stopwatch.
> Extinguish any flames.
> 4.2 If 30 seconds elapsed without smoke, terminate the test.
> 5. Report back to us the results, if necessary borrow a friend's
> computer to do so.
>
> Hmmm, why isn't anyone volunteering to do this testing?
>
> Seriously, How is the safe limit going to be determined?

I think Alexander had a good idea:

http://mailman.alsa-project.org/pipermail/alsa-devel/2015-March/089815.html

...now if this is chromebook, and I'm not sure whether that's the case 
or not, maybe "Windows" should be replaced with "Chrome OS", but anyhow 
- check what the supported OS is doing, and I believe Alexander 
suggested a safe way to do so.

Nikita - here's your chance to show that you're actually interested in 
getting the bug fixed, and not only to discuss whether alsamixer is a 
screwdriver or a microwave. On the physical hardware that has this 
problem, please perform the tests as Alexander suggested. And also run 
the alsa-info script on that hardware, and submit the result here.

-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic