Re: [PATCH 001/001] PCI: PCI quirk for Asus A8V and A8V Deluxe motherboards

[Andras Mantia <amantia@kde.org>]

Måns Rullgård wrote:

> It is the BIOS that disables the onboard sound if it detects a PCI
> sound card.  Chances are other vendors use different BIOS
> configurations that do not automatically disable things.  I don't know
> if messing with those bits might do something bad on another board.
> 

Yes, this might be a case, but you never know if ASUS engineers realize that
they can enable the board even if there is a PCI card and will include in
the next bios (as I wrote, they say it is impossible, but you never know).
So checking for ASUS will be wrong starting from that BIOS version.
When I first saw this bug on my system I searched a lot to see if I made a
wrong decision by buying ASUS and not another brand and everywhere on the
forums the same issue was described for other brands as well.

>From the code I would say that 
       pci_read_config_byte(dev, 0x50, &val);
       if (val & 0xc0) {

is the test if it's enabled by the bios or not, as after trying to enable
with 
pci_write_config_byte(dev, 0x50, val & (~0xc0));
it reads again the same byte and checks if the correct bits are enabled.

I see no harm here, but as I said I am not a hardware guy, just a desktop
programmer. ;-)

Andras

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