Re: PCI: disable I/O or mem before probing BAR size

[David Young <dyoung%pobox.com@localhost>]

On Mon, May 04, 2020 at 05:56:13PM -0400, Mouse wrote:
> On the other, if anything else could possibly be poking at the device
> while you're probing its mapping register to see how big it is, you've
> got much worse problems already.

If CPU 2 tries to read/write registers on device B while CPU 1 probes
device A's BAR for type/size, device A is enabled, and device A's base
address is momentarily undefined, then I can see device A and B both
responding to the same transaction and causing a fault to occur.

Dave

-- 
David Young
dyoung%pobox.com@localhost    Urbana, IL    (217) 721-9981