regulator: core: resolve supply for boot-on/always-on regulators

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@linaro.org>
Link: https://lore.kernel.org/r/20210519221224.2868496-1-dmitry.baryshkov@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index a31b6ae92a84e924bdf662e31887060902b3b14f..7fd793d8536cd624c503ff6cad4ed7cf410d59cb 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1381,6 +1381,12 @@ static int set_machine_constraints(struct regulator_dev *rdev)
         * 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) {