> -----Original Message-----
> Vishwanath Sripathy had written, on 12/13/2010 08:25 AM, the following:
> [...]
> >>>>>> + if (IS_PM34XX_ERRATUM(SDRC_WAKEUP_ERRATUM_i583)
> >> &&
> >>>>>> + (core_next_state == PWRDM_POWER_OFF))
> >> {
> >>>>>> + pwrdm_set_next_pwrst(core_pwrdm,
> >>>>>> PWRDM_POWER_RET);
> >>>>>> + core_next_state = PWRDM_POWER_RET;
> >>>>>> + }
> >>>>> Since next_state in pwrst_list (for core) is not updated, this is
> >>> throwing
> >>>>> up an error "Powerdomain (core_pwrdm) didn't enter target state
> >> 0"
> >>>> when
> >>>>> you off mode is enabled for ES1.1 or lesser (in suspend path).
It's
> >>> not
> >>>>> really true that Core has not entered target state. It has entered
> >>>>> Retention state which is the actual target state set in
> >>> omap_sram_idle.
> >>>>> However it did not enter the state that was passed by
> >>>> omap3_pm_suspend. Is
> >>>>> this expected behavior?
> >>>> we could go both ways on this - this patch will(as you noticed)
> >> indicate
> >>>> that the transition failed on <ES1.2, or we could make it entirely
> >>>> transparent(by modifying the the pwrst_list - claim we achieved
off,
> >>>> while not really hitting off - I personally dont think that is
> > correct.
> >>> The point I am making is that you cannot distinguish between genuine
> >> off
> >>> /retention failure since this message is thrown for both pass and
> > fail.
> >>> May be an additional trace message indicating that system entered
> >>> retention instead of off (for ES<1.2) will be useful.
> >> hmm... good point there.
> >> two issues here:
> >> a) omap3_pm_suspend should probably state which state was achieved
> >> as
> >> well in the error message (trivial fix).
> >> b) how do we notify users that it was due to
> >> SDRC_WAKEUP_ERRATUM_i583
> >> that core-off was denied. -> do this in omap3_pm_suspend(when user
> >> attempts actual OFF) OR omap3_pm_off_mode_enable(when user
> >> attempts to
> >> enable OFF mode)?
> >>
> >> Any suggestions to allow the same uImage boot on all silicon + allow
> >> cpu_idle + suspend paths not to spew pr_info messages(aka cant add
> >> prints in sram_idle)?
> > I vote for denying off mode for Core (for ES<1.2) in
> > omap3_pm_off_mode_enable and throw up a message saying that Core off
is
> > not enabled. Then we will not get this failure message in suspend path
> > since pwrst_list will have the right state.
> Keep in mind - if we disable it in omap3_pm_off_mode_enable - we will
> deny OFF wholesale if I understand the logic right- not just core-off -
> I kind of think that is extreme.
I take that back, we could do something like the following instead:
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index ba3c0d6..74842f1 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -933,7 +933,14 @@ void omap3_pm_off_mode_enable(int enable)
list_for_each_entry(pwrst, &pwrst_list, node) {
pwrst->next_state = state;
- omap_set_pwrdm_state(pwrst->pwrdm, state);
+ if (IS_PM34XX_ERRATUM(SDRC_WAKEUP_ERRATUM_i583) &&
+ pwrst->pwrdm == core_pwrdm) {
+ omap_set_pwrdm_state(pwrst->pwrdm,
PWRDM_POWER_RET);
+ pr_err("%s: cannot enable Core OFF due to i583\n",
+ __func__);
+ } else {
+ omap_set_pwrdm_state(pwrst->pwrdm, state);
+ }
}
}
Will wait to see if there are additional opinions on this approach -if
none,
Will post a v4 for this patch alone.
Regards,
Nishanth Menon
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