On Thu, 2012-07-12 at 15:11 +0530, Rajendra Nayak wrote:
> On Thursday 31 May 2012 06:59 PM, Tero Kristo wrote:
> > Previously, PER clock domain was always enabled, as the usecounts
> > for this domain incorrectly always showed positive value. On HW
> > level though, the domain enters idle as it is set in HW supervised
> > mode. Now, when the usecounts reflect real values, PER domain will
> > attempt to enter software supervised idle, which is not supported by the
> > hardware/kernel that well, and causes multiple problems. First of all,
> > coming back from idle, PER domain remains idle as the wakedeps have
> > been disabled for the domain, and this causes a crash with the GPIO
> > code, as the resume code attempts to access domain which is not active.
> > Just enabling the interface clocks for the GPIO does not help, as they
> > are autoidled and don't bring the domain out of idle. Secondly, there
> > are multiple erratas for omap3, which say that the wakedeps should be
> > enabled for the PER domain, see e.g. errata i582 for omap3630.
>
> If PER software supervised idle is so *buggy* then shouldn't the flags
> just reflect that PER *does not* support software supervised idle?
> Using a flag which reflects that the clkdm supports both hardware
> and software supervised idle ('CLKDM_CAN_HWSUP_SWSUP') and then using
> another one to actually skip putting it in software supervised sounds
> a little round about, no?
> Does updating the flag to 'CLKDM_CAN_HWSUP' also fix all the issues
> for you? without adding the additional 'CLKDM_SKIP_MANUAL_TRANS' flag.
Simple CAN_HWSUP doesn't work, as the whole problem is with HWSUP mode
and manual enabling / disabling of autodeps by kernel. I can rename the
flag to something like CLKDM_NO_AUTODEP_DISABLE and move the checking of
flag from the generic clockdomain code to omap3 clockdomain part though.
-Tero
>
> >
> > Signed-off-by: Tero Kristo<t-kristo@xxxxxx>
> > ---
> > arch/arm/mach-omap2/clockdomains3xxx_data.c | 2 +-
> > 1 files changed, 1 insertions(+), 1 deletions(-)
> >
> > diff --git a/arch/arm/mach-omap2/clockdomains3xxx_data.c b/arch/arm/mach-omap2/clockdomains3xxx_data.c
> > index 6038adb..0dae4c8 100644
> > --- a/arch/arm/mach-omap2/clockdomains3xxx_data.c
> > +++ b/arch/arm/mach-omap2/clockdomains3xxx_data.c
> > @@ -282,7 +282,7 @@ static struct clockdomain usbhost_clkdm = {
> > static struct clockdomain per_clkdm = {
> > .name = "per_clkdm",
> > .pwrdm = { .name = "per_pwrdm" },
> > - .flags = CLKDM_CAN_HWSUP_SWSUP,
> > + .flags = CLKDM_CAN_HWSUP_SWSUP | CLKDM_SKIP_MANUAL_TRANS,
> > .dep_bit = OMAP3430_EN_PER_SHIFT,
> > .wkdep_srcs = per_wkdeps,
> > .sleepdep_srcs = per_sleepdeps,
>
--
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
