Re: FireWire subsystem in development

Andreas Bombe (andreas.bombe@munich.netsurf.de)
Tue, 8 Jun 1999 23:02:58 +0200

On Mon, Jun 07, 1999 at 10:28:29AM +0900, Srdjan Sobajic wrote:
>
> > It seems to me that FireWire and USB both have the same configuration
> > issues to resolve, so sharing the higher level configuration between them
> > may be a cunning plan ...
> >
>
> I'm not sure what you meant by configuration issues, but a problem
> I see with that is that if we start supporting the 1394 hard drives
> then if someone changes the bus configuration the device names (if
> they are all hard-coded as with SCSI/IDE) would possibly change. (which
> doesn't seem like a good thing.)

That should be dealt with by reading the unique ID out of the devices'
ROMs after bus reset and let such high level code as block drivers
access the nodes through indirect handles instead of node IDs. That
has the advantage that you always have the device you want (hey, even
SCSI IDs change when people meddle with them :-). The disadvantage is
that the unique ID is 64 bits wide, and device nodes can't handle that
(unless we move to 128 bit device numbers...)

-- 
    Andreas E. Bombe <andreas.bombe@munich.netsurf.de>
    http://home.pages.de/~andreas.bombe/
RSA 0x886663c9  30 EC 09 73 84 7B 55 83  C4 7A 91 D9 9D C5 4B B0
DSA 0x04880A44 72E5 7031 4414 2EB6 F6B4  4CBD 1181 7032 0488 0A44


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/