The behavior of regulator_dev_lookup() for non-DT way has been broken
since the commit b8c325545714 ("regulator: Move OF-specific regulator
lookup code to of_regulator.c").

Before the commit, of_get_regulator() was used to get the regulator,
which returns NULL if the regulator is not found. So the regulator
will be looked up through regulator_lookup_by_name() if no matching
regulator is found in regulator_map_list.

However, currently, of_regulator_dev_lookup() is used to instead of
of_get_regulator(), but the variable 'r' is set to ERR_PTR(-ENODEV)
instead of NULL if the regulator is not found. In this case, if no
regulator is found in regulator_map_list, the variable 'r' is still
ERR_PTR(-ENODEV), So regulator_dev_lookup() returns the value of 'r'
directly instead of continuing to look up the regulator through
regulator_lookup_by_name().

Fixes: b8c325545714 ("regulator: Move OF-specific regulator lookup code to of_regulator.c")
Signed-off-by: Wei Fang <wei.fang@nxp.com>
---
 drivers/regulator/core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 835a5531d045..40dbff4017f5 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1965,6 +1965,9 @@ static struct regulator_dev *regulator_dev_lookup(struct device *dev,
 			return r;
 		if (PTR_ERR(r) == -EPROBE_DEFER)
 			return r;
+
+		if (PTR_ERR(r) == -ENODEV)
+			r = NULL;
 	}
 
 	/* if not found, try doing it non-dt way */
-- 
2.34.1

On Wed, 11 Sep 2024 20:03:38 +0800, Wei Fang wrote:
> The behavior of regulator_dev_lookup() for non-DT way has been broken
> since the commit b8c325545714 ("regulator: Move OF-specific regulator
> lookup code to of_regulator.c").
> 
> Before the commit, of_get_regulator() was used to get the regulator,
> which returns NULL if the regulator is not found. So the regulator
> will be looked up through regulator_lookup_by_name() if no matching
> regulator is found in regulator_map_list.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git for-next

Thanks!

[1/1] regulator: core: fix the broken behavior of regulator_dev_lookup()
      commit: a1d12410d9b1ecff87d39f80b0d1cec895012ffa

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark