On 11/28/2012 03:05 PM, Mike Turquette wrote:

Quoting Mark Langsdorf (2012-11-28 08:18:35)

quoted

On 11/28/2012 10:01 AM, Mike Turquette wrote:

quoted

Quoting Shawn Guo (2012-11-28 07:17:44)

quoted

On Wed, Nov 28, 2012 at 10:58:02PM +0800, Shawn Guo wrote:

quoted

On Wed, Nov 28, 2012 at 07:16:12AM -0600, Mark Langsdorf wrote:

quoted

I'd
have to move most of the logic of hb_set_target() into
clk_highbank.c:clk_pll_set_rate() and then add extra logic for when
cpufreq is not enabled/loaded.

You only need to move hb_voltage_change() into cpu clock's .set_rate()
hook with no need of checking if cpufreq is enabled or not.

Need to also check whether frequency or voltage should be changed first
in .set_rate() though.

Shawn

The notifiers in the clk framework might be a better place for this than
just simply hacking the logic into the .set_rate callback.

Unless the clk notifiers are different than the cpufreq notifiers, they
don't handle returning error conditions very well. And given that the
voltage change operation can fail (though it almost always succeeds on a
retry) I need to be able to handle and detect that error condition.

The notifier handler can handle the case where the transition fails (and
needs to be retried).

Also you should check out the clk notifiers.  I think they handle
failure decently.  If a notifer returns an error code then everything
unrolls and the clk_set_rate operation aborts.

Thanks for the pointer. The clk notifier calls seem to be working with
cpufreq-cpu0.

I did enough surgery on the code that I want to run a lot of stress
tests before I resubmit. I'll try to have something for Tuesday.

--Mark Langsdorf
Calxeda, Inc.