[PATCH v2] ARM: OMAP4: PM: Avoid expensive cpu_suspend() path for all CPU power states except off
santosh.shilimkar at ti.com
Wed Feb 13 03:55:24 EST 2013
Current CPU PM code code make use of common cpu_suspend() path for all the
CPU power states which is not optimal. In fact cpu_suspend() path is needed
only when we put CPU power domain to off state where the CPU context is lost.
Update the code accordingly so that the expensive cpu_suspend() path
can be avoided for the shallow CPU power states like CPU PD INA/CSWR.
The patch has been tested on OMAP4430 and OMAP5430(with few out of tree patches)
devices for suspend and CPUidle.
Cc: Kevin Hilman <khilman at deeprootsystems.com>
Reported-by: Richard Woodruff <r-woodruff2 at ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
Update changelog to include testing details as suggested
by Kevin Hilman.
arch/arm/mach-omap2/omap-mpuss-lowpower.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mach-omap2/omap-mpuss-lowpower.c b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
index aac46bf..abdd0f6 100644
@@ -276,7 +276,10 @@ int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
* Call low level function with targeted low power state.
- cpu_suspend(save_state, omap4_finish_suspend);
+ if (save_state)
+ cpu_suspend(save_state, omap4_finish_suspend);
* Restore the CPUx power state to ON otherwise CPUx
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