Re: [PATCH] net: avoid assigning ethaddr to wrong devices

[Sascha Hauer <sha@pengutronix.de>]

On Tue, Jun 26, 2018 at 08:42:37AM +0300, Nikita Yushchenko wrote:
> 
> 
> 25.06.2018 15:34, Sascha Hauer wrote:
> > Hi Nikita,
> > 
> > On Fri, Jun 22, 2018 at 07:30:12PM +0300, Nikita Yushchenko wrote:
> >> It can happen that device tree contains ethernetN alias pointing to
> >> valid device, but that device is not supported by [running instance of]
> >> barebox. Then ethN remains unassigned, and can be later captured by
> >> dynamically registered device such as usbnet.
> >>
> >> For such "stranger" device, ethaddr preconfigured for ethN should not be
> >> assigned. Also, ethaddr of such device should not be written to
> >> ethernetN node of device tree passed to kernel being booted.
> >>
> > 
> > There's only one usecase for matching edev->dev.id against the ethernetx
> > alias which has been introduced with:
> > 
> > | commit a78431c7fc42193be252417bf06f7cc61765a51e
> > | Author: Renaud Barbier <renaud.barbier@ge.com>
> > | Date:   Wed Sep 4 08:37:03 2013 +0200
> > | 
> > |     net, of: fixup MAC address by alias
> > |     
> > |     If a network device has not been registered from the devicetree, we may
> > |     still find it by its alias in the devicetree. This way also platform based
> > |     network devices can obtain a valid MAC address in the devicetree.
> > |     
> > |     Signed-off-by: Renaud Barbier <renaud.barbier@ge.com>
> > |     Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> > 
> > Your eth_is_stranger() returns true for the devices that Renaud wanted
> > to support, so instead of applying your patch we could equally well
> > revert that from Renaud.
> > 
> > I don't have a good idea right now how to fix this. Maybe we have to
> > make sure that ethernet devices from dynamic buses never get an id
> > asigned that is also present in the aliases node.
> 
> eth_is_stranger() for ethN returns true only if ethernetN alias exists
> AND ethN either does not have device tree node, or has node different
> from what is pointed by alias.
> 
> My assumption was that if under linux ethdevice is configured via device
> tree node with ethernetX alias, then under barebox it should also be
> configured via device tree node with same alias.
> 
> You mean, there is hardware that breaks this assumption?
> Which hardware it is?

It's PowerPC hardware which on barebox is not probed from devicetree, so
indeed there is no device node.

Sascha

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox