ARM: OMAP4+: PM: Restore CPU power state to ON with clockdomain force wakeup method
authorSantosh Shilimkar <santosh.shilimkar@ti.com>
Fri, 8 Feb 2013 17:20:58 +0000 (22:50 +0530)
committerKevin Hilman <khilman@linaro.org>
Fri, 5 Apr 2013 21:19:25 +0000 (14:19 -0700)
commitb7806dc7cba840ea538706621486475d93a53c55
tree934e1b306991d96755cb1babceefa3ed77b3944f
parentc309f7f46167e85d1aae2fd31f23e7d2b5cdfbe0
ARM: OMAP4+: PM: Restore CPU power state to ON with clockdomain force wakeup method

While waking up CPU from off state using clock domain force wakeup, restore
the CPU power state to ON state before putting CPU clock domain under
hardware control. Otherwise CPU wakeup might fail. The change is recommended
for all OMAP4+ devices though the PRCM weakness was observed on OMAP5
devices first.

As a result of weakness, lock-up is observed inside the hardware state
machine of local CPU PRCM and results are UN-predictable as per designers.
In software testing, we have seen hard-locks most of the time where system
gets frozen. With power domain state restored, system behaves correctly.

So update the code accordingly.

Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
arch/arm/mach-omap2/cpuidle44xx.c
arch/arm/mach-omap2/omap-smp.c