Re: Raspberry Pi 4 DMA range fix

[Jason Thorpe <thorpej%me.com@localhost>]

> On May 3, 2022, at 2:46 PM, Jared McNeill <jmcneill%invisible.ca@localhost> wrote:
> 
> That patch isn’t quite right because _DMA restrictions apply only to children of the bus that it appears on (ACPI 6.4 section 6.2.4). So yeah, we want _DMA to apply to PCI devices that are a child of the PCI0 device here, but this isn’t the right way to go about it.
> 
> I think we need to special case this for acpipchb because we don’t really have a clean way of expressing the relationship between a PCI device and firmware tables.

Do you mean a PCI bus instance or a child device of the PCI bus?

-- thorpej