Re: Problems with hda

On 11/04/10 12:45, Alexander Motin wrote:
> Doug Barton wrote:
>> Thanks to a generous FreeBSD user I have a shiny new Dell Optiplex 960,
>> with the following device:
>>
>> hdac0:<Intel 82801JD High Definition Audio Controller>  mem
>> 0xf7adc000-0xf7adffff irq 16 at device 27.0 on pci0
>> hdac0: HDA Driver Revision: 20100226_0142
>> hdac0: HDA Codec #0: Analog Devices AD1984A
>> pcm0:<HDA Analog Devices AD1984A PCM #0 Analog>  at cad 0 nid 1 on hdac0
>> pcm1:<HDA Analog Devices AD1984A PCM #1 Analog>  at cad 0 nid 1 on hdac0
>>
>> There's 2 problems. When I plug the headphones in there are sounds,
>> sometimes a low-level sound like a tea kettle whistling, and sometimes a
>> louder screeching sound.
>
> Try to play with mixer. Especially with "speaker", if you have it. Some
> unconnected CODEC inputs may receive random radio interference from
> other system components.

Bang on! Setting speaker to 0:0 instantly removed the random sounds. I 
assumed it was RFI from something, but I was using the windowmaker mixer 
app previously and thought I had already adjusted everything to 0. Silly 
of me not to check the command line version, thanks for the reminder.

>> The other problem is that the front headphone
>> jack doesn't work. The rear one works, but this is less than convenient.
>> :)
>
> Have you tried to playback via pcm1? It could go exactly there.

2 for 2! The magic is hw.snd.default_unit=1

>> Windows and ubuntu linux do not have either problem with the same
>> hardware.
>
> Linux and Windows often have hardcoded drivers for specific hardware.
> Our driver tries to be universal and honor standards, unluckily often
> violated by BIOS makers.

So, same song, $N'th verse? :)

> For more information about CODEC and it's configuration you need to get
> verbose dmesg. Details are in snd_hda(4).

Thank you for your excellent help, I learned something today. :)


Doug

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