Disable a PCI device

[Jorge Fernandez Monteagudo]

Hi,

Is there some way to disable a PCI device in coreboot using code to avoid to be listed once linux kernel is running?
I want the device '00:01.0 Class 0300: Device 1002:9874 (rev 84)' to dissapear from the lspci command if some
condition is met in the coreboot. I don't want to do it modifying the devicetree.cb... 
Now I'm using 'dev_set_enabled(vga_onboard, 0);' and is working ok avoiding the vgabios load but still apears the
device in lspci.

Thanks!
Jorge

[Peter Stuge]

Jorge Fernandez Monteagudo wrote:
> Is there some way to disable a PCI device in coreboot using code to
> avoid to be listed once linux kernel is running?

Some chipsets support that, but AFAIK this "feature" isn't modelled
in coreboot, so you're left with hacking something board-specific.
> I want the device '00:01.0 Class 0300: Device 1002:9874 (rev 84)' to
> dissapear from the lspci command

Whether you can or not will depend on the capabilities of 00:00.0.
Some have registers to block decoding for integrated devices.
Sometimes they are documented. Sometimes not.

//Peter

[Jorge Fernandez Monteagudo]

Hi Peter, thanks for the info!
> Whether you can or not will depend on the capabilities of 00:00.0.
> Some have registers to block decoding for integrated devices.
> Sometimes they are documented. Sometimes not.

I've found a register to do what I want:
D0F0x7C IOC Configuration Control
bit 0 : ForceIntGfxDisable: internal graphics disable. Read-write. Setting this bit disables the internal graphics and the HD Audio Controller.

and it works :)