The kernel expects the power_off function to not return, and if it does it panics. At 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@xxxxxxxxxx> --- drivers/mfd/axp20x.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c index 6364dab..fd80b09 100644 --- a/drivers/mfd/axp20x.c +++ b/drivers/mfd/axp20x.c @@ -17,6 +17,7 @@ */ #include <linux/err.h> +#include <linux/delay.h> #include <linux/interrupt.h> #include <linux/kernel.h> #include <linux/module.h> @@ -677,6 +678,9 @@ 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) -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
