[PATCH RESEND] ARM: l2x0: add three special L210 aux control flags

Russell King - ARM Linux linux at arm.linux.org.uk
Tue Apr 5 01:08:27 PDT 2016


On Tue, Apr 05, 2016 at 12:36:40AM +0100, Russell King - ARM Linux wrote:
> On Mon, Apr 04, 2016 at 06:29:26PM -0500, Josh Cartwright wrote:
> > Similarly, we're waiting on feedback for:
> > 
> >   http://lkml.kernel.org/r/1456761716-10174-1-git-send-email-brad.mouring@ni.com
> > 
> > Also in the queue; also w/ Rob's Ack.  There was a change awhile back to
> > unconditionally enable the power-management features of the PL310 which
> > caused a noticeable performance degradation on our boards; placing the
> > PM options behind a togglable DT property provides us an out.
> 
> For that one, I've been wondering why it's seemingly acceptable to
> start throwing *errors* for *new* DT properties which weren't required
> before.  Also, there's no DT documentation for the new properties,
> which is a fundamental requirement - and Rob should not have given
> his ack without there being a DT documentation patch.
> 
> Obviously, the kernel review process has broken on this one... or
> I must remember this sneaky trick for getting new DT properties in
> without the required documentation...

There's another issue here - we go from enabling these options by
default to leaving them as the firmware specified them.  While that's
something I approve of, I'm not happy because it means all platforms
that have these PM bits enabled today could end up losing them - so
it's a PM regression waiting to happen.  Who's going to add them to
all the dt blobs where platforms _can_ cope with having these PM bits
enabled?

-- 
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