On Wed, Sep 14, 2011 at 08:07:39PM +0100, Russell King - ARM Linux wrote:

On Mon, Sep 12, 2011 at 01:41:41PM +0800, Shawn Guo wrote:

quoted

OMAP and IMX6Q retains L2 cache, we have to go save/restore approach
to work with generic cpu_suspend/resume routines.  But for platforms
that will power off L2 during suspend, I think re-init is the easiest
way for them get L2 back to work.

It would be much better to re-init with the same configuration values
used during the initial init - rather than using the mask + values
method which preserves whatever the boot loader gave us.

The re-init approach calls the exactly same function used for the
initial init during resume.  So if this is a problem, it's the problem
of initial init.  The initial init code should initialize the L2 into
a known state with "values" rather than "mask + values" method.

We know with quite a bit of experience that we can't rely on boot loaders
setting things up in the same way on initial boot and resume, so we should
not rely on the boot loader setting the same L2 configuration on resume
as was set during boot.

Right, we should not reply on boot loader.  My point is we should not
reply on boot loader on the initial boot.  Then we can get the same
L2 configuration on resume as was set during initial boot.

-- 
Regards,
Shawn