[U-Boot] Start/stop of network devices (was: Re: [PATCH] UEC PHY: Speed up initial PHY neg.)

[Detlev Zundel]

Hi Ben,

[Jocke deleted from CC as this is not about the patch anymore]

> Sorry for the delay on this.  I'm all for changing the existing
> behavior.  It seems to me that the only time we would ever want to
> wind an interface down is if we switch the active one (even then, I'm
> not sure).  My world view is limited, but I can't imagine that even
> changing interfaces happens much in real world U-boot usage, that is
> the non-lab, non-interactive use cases.  What would you think about
> adding something like ifup and ifdown commands so that users could
> explicitly start/stop interfaces?

Actually I was thinking of an automatic initialisiation once we do a
network transfer.  This would be more in line with the current command
line interface.  For this we would need a state variable per device and
start the device if it is down.

The "ifdown" _may_ be implemented as a command, but I think this should
be done automatically once we boot a kernel.  For USB we already have to
do something like this as USB host controllers tend to DMA frame numbers
into memory as long as they are running.  This was an especially
difficult problem to diagnose back then.  From this lesson I think we
should learn and call "stop" methods for every initialized device.

What do you think?

Once more this is going into the "device" model dicussion that we
already thought about a while ago [1].  Maybe someday somebody finds
some time and starts to work on it ;)

Cheers
  Detlev

[1] http://www.denx.de/wiki/view/U-Boot/OLSUbootBOF

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A foolish consistency is the hobgoblin of little minds.
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