Hi Paul,

On Thu, Mar 10, 2011 at 2:04 AM, Paul Walmsley [off-list ref] wrote:

On Thu, 3 Mar 2011, Jean Pihet wrote:

quoted

The patch adds the new power management trace points for
the OMAP architecture.

The trace points are for:
- default idle handler. Since the cpuidle framework is
? instrumented in the generic way there is no need to
? add trace points in the OMAP specific cpuidle handler;
- cpufreq (DVFS),
- SoC clocks changes (enable, disable, set_rate),
- power domain states: the desired target state and -if different-
? the actually hit state.

Because of the generic nature of the changes, OMAP3 and OMAP4 are supported.

Tested on OMAP3 with suspend/resume, cpuidle, basic DVFS.

Signed-off-by: Jean Pihet <redacted>

In terms of tracing powerdomain state changes, since OMAP powerdomains can
potentially transition without the MPU knowing about it, some powerdomain
transitions will be missed by these. ?(The software counters miss them
too.) ?The only way to be certain about these is to watch the debug
observability lines. ?Still, it is the rare board that brings out debobs
lines. ?So this seems reasonable, as long as people don't expect 100%
coverage.

OK that is correct. The events are tracing SW events only, i.e. a
trace is generated when a decision is made wrt next power states,
clock changes etc.
A remark: the OMAP4+ HW tracing modules do support the changes of
power domains states. There definitely is more to come on that topic!

Thanks for reviewing!
Jean

For the clock and powerdomain changes,

Acked-by: Paul Walmsley <paul@pwsan.com>


- Paul