leds: handle suspend/resume in heartbeat trigger

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The following phenomena was observed: when suspending the
system, sometimes the heartbeat LED was left on, glowing and
wasting power while the rest of the system is asleep, also
disturbing power dissapation measures on the odd suspend
cycle when it's left on.

Clearly this is not how we want the heartbeat trigger to
work: it should turn off and leave the LED off during
system suspend.

This removes the heartbeat trigger when preparing suspend and
restores it during resume. The trigger code will make sure all
LEDs are left in OFF state after removing the trigger, and
will re-enable the trigger on all LEDs after resuming.

Cc: linux-pm@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

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Linus Walleij 2016-06-08 10:29:48 +02:00 • committed by Jacek Anaszewski

parent 7cfe749fad

commit 5ab92a7cb8

1 changed files with 31 additions and 0 deletions

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drivers/leds/trigger/ledtrig-heartbeat.c

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