On Tue, 2012-07-03 at 18:15 +0200, Nicolas Ferre wrote:

On 07/03/2012 05:47 PM, Arvid Brodin :

quoted

(Added MACB "patch" contact Nicolas Ferre to CC list.)

Hi,

(adding linux-arm-kernel)

quoted

On 2012-06-29 17:24, Ben Hutchings wrote:

quoted

On Fri, 2012-06-29 at 02:36 +0000, Arvid Brodin wrote:

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Hi,

After 'ip link set eth0 up' on an avr32 board (network driver macb), the device ends up in
operational mode "UNKNOWN":

# ip link
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
    link/ether 00:24:74:00:17:9d brd ff:ff:ff:ff:ff:ff

Unplugging and plugging in the network cable gets the device to mode "UP".

This is a problem for me because I'm trying to use this device as a "slave" device (for a
virtual HSR device*) and I need to be able to decide if the slave device is operational or
not.

Following Stephen's advice here:
http://kerneltrap.org/mailarchive/linux-netdev/2008/9/24/3398834 I checked the macb.c code
and noticed they do not call netif_carrier_off() neither before register_netdev() nor in
dev_open().

quoted

It should be called after register_netdev() and before the driver's
ndo_open implementation returns.

After having read several drivers, it seems that some are calling
netif_carrier_off() *before* register_netdev() and some *after*... What
is the proper way?

[...]

The latter is correct; the former is a bug that is tolerated for now:

http://article.gmane.org/gmane.linux.network/111355/

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.