Commit 179dc63d authored Jun 05, 2016 by Hans de Goede Committed by Lee Jones Jun 29, 2016

mfd: axp20x: Add a 500ms delay at the end of axp20x_power_off



The kernel expects the power_off function to not return, and if it does
it panics. Add a slight delay after the i2c write which turns off power
through the PMIC, to give capacitors etc. some time to drain.

Without this the kernel lives on long enough after the poweroff to
print the following on the serial console on my Mele A1000G quad:

[  248.583588] reboot: Power down
[  248.600490] Kernel pa

With the delay the start of printing "Kernel panic" is gone.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

parent 2be59755

drivers/mfd/axp20x.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -17,6 +17,7 @@
		*/

		#include <linux/err.h>
		#include <linux/delay.h>
		#include <linux/interrupt.h>
		#include <linux/kernel.h>
		#include <linux/module.h>
		@@ -667,6 +668,9 @@ static void axp20x_power_off(void)

		regmap_write(axp20x_pm_power_off->regmap, AXP20X_OFF_CTRL,
		AXP20X_OFF);

		/* Give capacitors etc. time to drain to avoid kernel panic msg. */
		msleep(500);
		}

		int axp20x_match_device(struct axp20x_dev *axp20x)

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