--- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1422,6 +1422,12 @@ static int set_machine_constraints(struc * and we have control then make sure it is enabled. */ if (rdev->constraints->always_on || rdev->constraints->boot_on) { + /* If we want to enable this regulator, make sure that we know + * the supplying regulator. + */ + if (rdev->supply_name && !rdev->supply) + return -EPROBE_DEFER; + if (rdev->supply) { ret = regulator_enable(rdev->supply); if (ret < 0) {