[PATCH RESEND 3/4] regulator: avoid resolve_supply() infinite recursion

[Michał Mirosław]

When a regulator's name equals its supply's name the
regulator_resolve_supply() recurses indefinitely. Add a check
so that debugging the problem is easier. The "fixed" commit
just exposed the problem.

Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Cc: stable at vger.kernel.org
Reported-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
Signed-off-by: Michał Mirosław <mirq-linux at rere.qmqm.pl>
---
 drivers/regulator/core.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index ad36f03d7ee6..ab922ed273f3 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1841,6 +1841,12 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)
 		}
 	}
 
+	if (r == rdev) {
+		dev_err(dev, "Supply for %s (%s) resolved to itself\n",
+			rdev->desc->name, rdev->supply_name);
+		return -EINVAL;
+	}
+
 	/*
 	 * If the supply's parent device is not the same as the
 	 * regulator's parent device, then ensure the parent device
-- 
2.20.1