Re: [PATCH] smsc75xx: only set mac address once on bind

Hi Dan,

On 10 December 2012 23:00, Dan Williams [off-list ref] wrote:

On Mon, 2012-12-10 at 11:01 +0000, Steve Glendinning wrote:

quoted

This patch changes when we decide what the device's MAC address
is from per ifconfig up to once when the device is connected.

Without this patch, a manually forced device MAC is overwritten
on ifconfig down/up.  Also devices that have no EEPROM are
assigned a new random address on ifconfig down/up instead of
persisting the same one.

Does this mean that on devices without EEPROM, ifconfig XXX
down/ifconfig XXX up will generate a *new* random address?  That seems a
bit odd; why wouldn't the first random address generated for the device
persist until either (a) changed by ifconfig or (b) device was
disconnected?

Sorry if my commit message wasn't clear enough.  That is indeed a bit
odd, and it describes the (buggy) behaviour BEFORE this patch was
applied.

With this patch applied, devices without EEPROM (and without a
manually specified MAC address) will get a randomly generated address
assigned once at bind time, so this MAC will persist for the lifetime
the USB device is connected.  We also now won't trash a manually
specified MAC, for cases where userland sets the MAC before bringing
up the interface.

-- 
Steve Glendinning