It appears that this patch causes incorrect reference counting on supply
regulators if the child regulator is enabled with for example boot_on=true:
commit b2296bd43e781976743354c668a356b0df98e1da
Author: Laxman Dewangan<ldewangan@xxxxxxxxxx>
Date: Mon Jan 2 13:08:45 2012 +0530
regulator: Enable supply regulator if child rail is enabled.
If a regulator is enabled at boot (by constraints), then this patch calls
regulator_enable() on the supply regulator, leading to a use_count increase on
the supply. However, this patch adds no code to perform the corresponding
regulator_disable(), leaving the supply regulator on even when all consumers
have disabled it.
AFAICS, this patch would have only worked for always_on regulators.