[PATCHv4 4/8] ARM: OMAP3: add manual control for mpu / core pwrdm usecounting

Kevin Hilman [off-list ref] writes:

Tero Kristo [off-list ref] writes:

quoted

mpu / core powerdomain usecounts are now statically increased
by 1 during MPU activity. This allows the domains to reflect
actual usage, and will allow the usecount to reach 0 just before
all CPUs are ready to idle. Proper powerdomain usecounts are
propageted to voltagedomain level also, and will allow vc
callbacks to be triggered at right point of time.

Signed-off-by: Tero Kristo <redacted>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <redacted>

IMO, the idea is fine, but I'm not crazy about the implementation in
powerdomain.c, which is meant for pwrdm generic code.   In particular,
I'm not crazy about the pwrdm lookups in powerdomain.c.

Since pm<soc>.c already has references to mpu_pwrdm and core_pwrdm, why
not just add the pwrdm_clkdm_enable/disable calls directly in pm<soc>.c

Also, the changelog should be a bit more specific about why CORE
powerdomain is also handled here when most of the code only talks about
the CPU.

After playing with this some more, and doing a test hack of my idea
above, along with the per-pwrdm pre/post changes now in mainline, I
thinks this series should go one step further.

Basically, we should be able to get rid of the calls to
prdm_pre|post_transition that are outside the powerdomain code.  With
the addition of pwrdm_clkdm_enable|disable, it seems that the pre|post
transition calls should be called directly from
pwrdm_clkdm_enable|disable when the usecount transitions to/from zero.

Kevin