ACPI / EC: Add PM operations for suspend/resume noirq stage

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It is reported that on some platforms, resume speed is not fast. The cause
is: in noirq stage, EC driver is working in polling mode, and each state
machine advancement requires a context switch.

The context switch is not necessary to the EC driver's polling mode. This
patch implements PM hooks to automatically switch the driver to/from the
busy polling mode to eliminate the overhead caused by the context switch.

This finally contributes to the tuning result: acpi_pm_finish() execution
time is improved from 192ms to 6ms.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Reported-and-tested-by: Todd E Brandt <todd.e.brandt@linux.intel.com>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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Lv Zheng 2016-08-03 09:07:58 +08:00 • committed by Rafael J. Wysocki

parent 694d0d0bb2

commit df45db6177

2 changed files with 55 additions and 0 deletions

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53

drivers/acpi/ec.c

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2

drivers/acpi/internal.h

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