On 11/03/2012 01:17 PM, Bedia, Vaibhav wrote:
On Sat, Nov 03, 2012 at 17:45:03, Kevin Hilman wrote:
On 11/02/2012 01:32 PM, Vaibhav Bedia wrote:
From: Vaibhav Hiremath <hvaibhav@xxxxxx>
The current OMAP timer code registers two timers -
one as clocksource and one as clockevent.
AM33XX has only one usable timer in the WKUP domain
so one of the timers needs suspend-resume support
to restore the configuration to pre-suspend state.
The changelog describes "what", but doesn't answer "why?"
Sorry I'll try to take of this in the future.
Thanks. Here's a general rule. Assume you (or I) will be reading this
a year from now and will have forgotten the details. The changelog then
serves as our long-term memory. :)
commit adc78e6 (timekeeping: Add suspend and resume
of clock event devices) introduced .suspend and .resume
callbacks for clock event devices. Leverages these
callbacks to have AM33XX clockevent timer which is
in not in WKUP domain to behave properly across system
suspend.
You say it behaves properly without describing what improper
behavior is happening.
There are two issues. One is that the clockevent timer doesn't
get idled which blocks PER domain transition. The next one is that
the clockevent doesn't generate any further interrupts once the
system resumes.
Please include both in the next rev of the changelog.
We need to restore the pre-suspend configuration.
I haven't tried but I guess we could have used the save and restore
c timer registers here.
Yes, please try with that. Won't that be necessary anyways for situations
where the powerdomain goes off?
Kevin
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
