virtio — archive

[PATCH] pci: missing documentation for dealing with 64 bit config fields

From: Cornelia Huck <[email protected]>
To: [email protected]
Date: Thu, 02 Apr 2015 10:24:00 -0000

On Thu, 2 Apr 2015 12:06:41 +0200 "Michael S. Tsirkin" <[email protected]> wrote: > On Thu, Apr 02, 2015 at 11:01:45AM +0200, Cornelia Huck wrote: > > On Wed, 1 Apr 2015 20:42:13 +0200 > > "Michael S. Tsirkin" <[email protected]> wrote: > > > +For device configuration access, the driver MUST use 8-bit wide > > > +accesses for 8-bit wide fields, 16-bit wide and aligned accesses > > > +for 16-bit wide fields and 32-bit wide and aligned accesses for > > > +32-bit and 64-bit wide fields. For 64-bit fields, the driver MAY > > > +access each of the high and low 32-bit parts of the field > > > +independently. > > > > Doesn't the last sentence follow from "use 32-bit wide accesses" > > already? > > Someone might assume that driver must always access low part, > then high part. Last sentence says it does not have to. > OK, that clears it up then.