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| author | Santosh Shilimkar <santosh.shilimkar@ti.com> | 2013-02-08 22:50:58 +0530 |
|---|---|---|
| committer | Kevin Hilman <khilman@linaro.org> | 2013-04-05 14:19:25 -0700 |
| commit | b7806dc7cba840ea538706621486475d93a53c55 (patch) | |
| tree | 934e1b306991d96755cb1babceefa3ed77b3944f /arch/arm/mach-omap2/cpuidle44xx.c | |
| parent | c309f7f46167e85d1aae2fd31f23e7d2b5cdfbe0 (diff) | |
| download | lwn-b7806dc7cba840ea538706621486475d93a53c55.tar.gz lwn-b7806dc7cba840ea538706621486475d93a53c55.zip | |
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>
Diffstat (limited to 'arch/arm/mach-omap2/cpuidle44xx.c')
| -rw-r--r-- | arch/arm/mach-omap2/cpuidle44xx.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/cpuidle44xx.c b/arch/arm/mach-omap2/cpuidle44xx.c index 944e64aad7e5..9de47a70628f 100644 --- a/arch/arm/mach-omap2/cpuidle44xx.c +++ b/arch/arm/mach-omap2/cpuidle44xx.c @@ -131,6 +131,7 @@ static int omap4_enter_idle_coupled(struct cpuidle_device *dev, /* Wakeup CPU1 only if it is not offlined */ if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) { clkdm_wakeup(cpu_clkdm[1]); + omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON); clkdm_allow_idle(cpu_clkdm[1]); } |