On Tue, Nov 13, 2018 at 10:39:15PM +0000, Alex_Gagniuc@xxxxxxxxxxxx wrote: > On 11/12/2018 11:02 PM, Bjorn Helgaas wrote: > > The whole issue of firmware-first, the mechanism by which firmware > > gets control, the System Error enables in Root Port Root Control > > registers, etc., is very murky to me. Jon has a sort of similar issue > > with VMD where he needs to leave System Errors enabled instead of > > disabling them as we currently do. > > Well, OS gets control via _OSC method, and based on that it should > touch/not touch the AER bits. The bits that get set/cleared come from > _HPX method, and there's a more about the FFS described in ACPI spec. It > seems that if platform, wants to enable VMD, it should pass the correct > bits via _HPX. I'm curious to know in what new twisted way FFS doesn't > work as intended. When VMD is enabled, the platform sees a VMD endpoint. It doesn't see any of the root ports on that domain, so ACPI can't provide policies for them nor AER registers for the platform to consider controlling.
