From: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> commit 98e48cd9283dbac0e1445ee780889f10b3d1db6a upstream. For the boot-on/always-on regulators the set_machine_constrainst() is called before resolving rdev->supply. Thus the code would try to enable rdev before enabling supplying regulator. Enforce resolving supply regulator before enabling rdev. Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator") Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210519221224.2868496-1-dmitry.baryshkov@xxxxxxxxxx Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/regulator/core.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1191,6 +1191,12 @@ 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) {