From: Michał Mirosław <mirq-linux@xxxxxxxxxxxx> commit cf1ad559a20d1930aa7b47a52f54e1f8718de301 upstream. regulator_get_voltage_rdev() is called in regulator probe() when applying machine constraints. The "fixed" commit exposed the problem that non-bypassed regulators can forward the request to its parent (like bypassed ones) supply. Return -EPROBE_DEFER when the supply is expected but not resolved yet. Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx> Reported-by: Ondřej Jirman <megous@xxxxxxxxxx> Reported-by: Corentin Labbe <clabbe.montjoie@xxxxxxxxx> Tested-by: Ondřej Jirman <megous@xxxxxxxxxx> Link: https://lore.kernel.org/r/a9041d68b4d35e4a2dd71629c8a6422662acb5ee.1604351936.git.mirq-linux@xxxxxxxxxxxx Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/regulator/core.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -4128,6 +4128,8 @@ int regulator_get_voltage_rdev(struct re ret = rdev->desc->fixed_uV; } else if (rdev->supply) { ret = regulator_get_voltage_rdev(rdev->supply->rdev); + } else if (rdev->supply_name) { + return -EPROBE_DEFER; } else { return -EINVAL; }