RE: [PATCH] bnx2: turn off the network statck during initialization

On Thu, 2012-08-16 at 20:28 +0000, Jiang Wang wrote:
[...]

Also, I have another comment related to link state.

Right now, the bnx2 driver powers up the device in bnx2_init_board(),
regardless the netif_carrier is on or off. This may introduce
following inconsistent behaviors:
1) suppose the cable is plugged in to the NIC and the other end is
connected to a switch
2) user powers up the box
3) the Linux does not bring up the interface; i.e, ifconfig ethx shows
it is down

Most distributions will bring up all interfaces at boot, by default.

4) ethtool ethx will show no link
5) if the user goes to check the light on the physical NIC, he will
see the green link light is ON. That means the link is up, right? 

I think it is better to power down the device until bnx2_open is
called. In this way, ethtool report and the physical link light will
be consistent. 

[...]

In general, a physical network interface may need to be enabled to allow
management traffic to a BMC, even when the interface is in the 'down'
state on the host.

The link state should be considered unknown whenever the interface is
down, and /sys/class/net/$IFACE/carrier is not readable then.  However
ETHTOOL_GLINK is not expected to fail in this way, and must always
return 0 (down) or 1 (up).  The convention (which is now enforced in
ethtool_get_link()) is that when the interface is down it should always
return 0.

Ben.

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Ben Hutchings, Staff Engineer, Solarflare
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