On Thu, Dec 01, 2011 at 11:30:16AM -0700, Paul Walmsley wrote:

So for example, if you had a driver that did:

c = clk_get(dev, clk_name);
clk_enable(c);
clk_set_rate(c, clk_rate);

and c was currently not enabled by any other driver on the system, and 
nothing else had called clk_block_rate_change(c), then the rate change 
would be allowed to proceed.  (modulo any notifier activity, etc.)  

So clk_{allow,block}_rate_change() was simply intended to allow or 
restrict other users of the same clock, not the current user.

Ah, sorry!  I'd totally misunderstood what you were proposing.