The jiffies-based off_on_delay implementation has a couple of problems
that cause it to sometimes not actually delay for the required time:
(1) If, for example, the off_on_delay time is equivalent to one jiffy,
and the ->last_off_jiffy is set just before a new jiffy starts,
then _regulator_do_enable() does not wait at all since it checks
using time_before().
(2) When jiffies overflows, the value of "remaining" becomes higher
than "max_delay" and the code simply proceeds without waiting.
Fix these problems by changing it to use ktime_t instead.
[Note that since jiffies doesn't start at zero but at INITIAL_JIFFIES
("-5 minutes"), (2) above also led to the code not delaying if
the first regulator_enable() is called when the ->last_off_jiffy is not
initialised, such as for regulators with ->constraints->boot_on set.
It's not clear to me if this was intended or not, but I've preserved
this behaviour explicitly with the check for a non-zero ->last_off.]
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/20210423114524.26414-1-vincent.whitchurch@axis.com
Signed-off-by: Mark Brown <broonie@kernel.org>
a8ce7bd896