[PATCH v2 1/2] ARM: kirkwood: Ensure that kirkwood_ge0[01]_init() finds its clock

Jason Gunthorpe jgunthorpe at obsidianresearch.com
Tue Jan 29 12:29:17 EST 2013


On Tue, Jan 29, 2013 at 07:56:46AM +0100, Andrew Lunn wrote:
> On Mon, Jan 28, 2013 at 11:28:18AM -0700, Jason Gunthorpe wrote:
> > On Sun, Jan 27, 2013 at 03:53:53PM +0100, Sebastian Hesselbarth wrote:
> > 
> > > I just want Simon to confirm that Kirkwood's gbe is really loosing the
> > > contents of its MAC address registers during gated clocks, which is from
> > > a HW point of view very unlikely.
> > 
> > FWIW, there are two block power management controls on the kirkwood
> > chips, one is documented to a clock gate, and one is documented to a
> > be a power down.

> Are you referring to 
> 
> Memory Power Management Control Register
> Offset: 0x20118

Yes, and the other is 'Clock Gating Control Register' at 2011c.

I suppose Linux should really used both for maximum power savings,
probably in a clock off, then power off kind of pattern??

Jason



More information about the linux-arm-kernel mailing list