On Thu, 2012-05-31 at 18:40 -0500, Jon Hunter wrote:

Hi Tero,

On 05/31/2012 08:29 AM, Tero Kristo wrote:

quoted

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.

Signed-off-by: Tero Kristo <redacted>
---
 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,

So this change is just preventing software from clearing the wakeup-deps
and keeping the PER clock domain always in HW_AUTO?

Basically yes.

Sorry for the dumb question, but what is the circumstance under which we
want to clear the wakeup-deps when we disable the clock domain? I am
just curious why this is being done in the first place.

Not sure, maybe Paul can answer that question. Personally I don't see
much point in fiddling with the wakedeps.

-Tero