Subject: [PATCH 3/4] clk: kirkwood: Add CLK_IGNORE_UNUSED to ethernet ge0 and ge1 clocks

From: [email-masked] (Thomas Petazzoni)
Date: Tue, 1 Oct 2013 17:33:58 +0200

Dear Jason Cooper,

On Tue, 1 Oct 2013 11:15:28 -0400, Jason Cooper wrote:

> > Sorry for jumping into the discussion, but how does that solve the case
> > when the driver is loaded as a module, and therefore unused clocks are
> > disabled before the driver ->probe() function gets called?
> 
> Sorry, I wrote the reply to JasonG just moments before and assumed a
> little knowledge of that in this reply.
> 
> We would use Ezequiel's patch to ensure CLK_IGNORE_UNUSED is set for the
> clock during boot, then, after boot, mv643xx_eth's probe would look for
> the mac address in the DT.  If it's there, it would unset the flag
> knowing that it can recover the mac address from the DT.  Then we could
> get the power savings from suspend/unload.

Ah, ok. What was wrong with the idea of getting the MAC address from
the hardware early at boot time, and adjust the in-memory Device Tree
with this information, so that the mv643xx_eth driver can find them
whenever it gets loaded, and regardless of whether clocks have been
disabled or not?

Thomas
-- 
Thomas Petazzoni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com