Re: [PATCH] mfd: axp20x: Do not sleep in the power off handler

From: Dmitry Osipenko
Date: Sun Nov 06 2022 - 17:40:27 EST


On 11/6/22 00:29, Samuel Holland wrote:
> Since commit 856c288b0039 ("ARM: Use do_kernel_power_off()"), the
> function axp20x_power_off() now runs inside a RCU read-side critical
> section, so it is not allowed to call msleep(). Use mdelay() instead.
>
> Fixes: 856c288b0039 ("ARM: Use do_kernel_power_off()")
> Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>
> ---
>
> drivers/mfd/axp20x.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
> index 88a212a8168c..880c41fa7021 100644
> --- a/drivers/mfd/axp20x.c
> +++ b/drivers/mfd/axp20x.c
> @@ -842,7 +842,7 @@ static void axp20x_power_off(void)
> AXP20X_OFF);
>
> /* Give capacitors etc. time to drain to avoid kernel panic msg. */
> - msleep(500);
> + mdelay(500);
> }
>
> int axp20x_match_device(struct axp20x_dev *axp20x)

ARM was doing local_irq_disable() on power-off before
do_kernel_power_off() was introduced, so this should've been incorrect
for a couple years at least. If I'm not missing anything.

--
Best regards,
Dmitry