Re: Long-standing bugs and typos
Stephen Lee (sl14@crux1.cit.cornell.edu)
Wed, 6 Mar 1996 16:28:25 -0500
On Mar 6, 2:16pm, "Ulrich Windl" wrote:
>
> On 6 Mar 96 at 0:56, Stephen Lee wrote:
>
> > On Mar 5, 9:10pm, Johannes Kroeger wrote:
> > >
> > > Hello experts,
> > >
> > > Here is a small collection of bugs and typos that should be fixed before the
> > > next stable release.
> > >
> > Add this typo to your list...
>
> I'm not sure about this
>
> >
> > This is linux/include/linux/pci.h:
> >
> > --- pci.h- Wed Mar 6 01:01:45 1996
> > +++ pci.h Wed Mar 6 01:01:53 1996
> > @@ -536,8 +536,8 @@
> > * devices. The slot/function address of each device is encoded
> > * in a single byte as follows:
> > *
> > - * 7:4 = slot
> > - * 3:0 = function
> > + * 7:3 = slot
> > + * 2:0 = function
> > */
> > #define PCI_DEVFN(slot,func) ((((slot) & 0x1f) << 3) | ((func) & 0x07))
>
> I don't have the source here, but I guess the first number is the bit
> position while the second number is the length.
>
> 0x1f makes five bits for me (00011111); that is 7:5 for slot, and 2:3
> for function (if I'm assuming the semantics correctly). 0x07 makes
> three bits (00000111).
Even if they are bit:length, they still don't match the code below. I
think they are bit numbers, thus 7:3 means bit 7-3 (5 bits) and 2:0 mean
bits 2,1,0 (3 bits), matching the code. I think my way is closer to the
convention of specifying bits in a word.
Stephen
--
Stephen Lee
Internet: sl14@cornell.edu