maestro3 hardware volume control

[Scott Long]

Pyun YongHyeon wrote:
> On Sun, May 29, 2005 at 01:28:59AM +0300, Panagiotis Astithas wrote:
>  > Weird, on my HP Omnibook XE3, the on-board maestro3 has been working 
>  > flawlessly all along without any entry in /boot/device.hints. If I add:
>  > hint.pcm.0.hwvol_config="0"
>  > then the hardware volume controls on the laptop stop functioning. 
>  > Setting it to "1" makes it working again.
>  > 
> Hmm, I didn't know that due to a comment in the driver and
> failure on my laptops.
> 
>  > Does that mean that GPIO pin 4,5 was selected as the default by some 
>  > other means on my system? Could ACPI be doing it?
>  > 
>  > 
> I guess your system use GD pins to control hardware volume.
> Stock maestro3 driver uses
> 
> hint.pcm.0.hwvol_config="0" : select GPIO pin
> hint.pcm.0.hwvol_config="1" : select GD pin
> (This is reverse of my previous posting, sorry, I'm confused.)
> If there is no hint then it will use GD pin.
> 
> Having a quirk table for sytems would be better solution.
> But it's hard to build a complete table for this. Since there is
> a system that works with current driver's behavior it would be
> useless to change default to use GD pin. I can live with the hint
> mechanism. However the drawback is the hint mechanism works only
> at boot time for staticlly linked driver, so it's not apply to
> dynamically loaded driver. :-(
> 

It might be possible to examine the system SMBIOS table for the make and
model of the system and use them as keys for a quirk table.  Of course
it will only work for systems like laptops that have the M3 or A1 chip
embedded.  sigh.  I think that this all works in the Windows world
because the hardware maker provides a driver that is customized 
appropriately.

Scott