[PATCH] regulator: core: Return error in get optional stub

[PATCH] regulator: core: Return error in get optional stub

[Tim Kryger]

Drivers that call regulator_get_optional are tolerant to the absence of
that regulator.  By modifying the value returned from the stub function
to match that seen when a regulator isn't present, callers can wrap the
regulator logic with an IS_ERR based conditional even if they happen to
call regulator_is_supported_voltage.  This improves efficiency as well
as eliminates the possibility for a very subtle bug.

Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
---

This change was proposed here: https://lkml.org/lkml/2014/4/16/627

 include/linux/regulator/consumer.h |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/regulator/consumer.h b/include/linux/regulator/consumer.h
index e530681..1a4a8c1 100644
--- a/include/linux/regulator/consumer.h
+++ b/include/linux/regulator/consumer.h
@@ -258,14 +258,14 @@ regulator_get_exclusive(struct device *dev, const char *id)
 static inline struct regulator *__must_check
 regulator_get_optional(struct device *dev, const char *id)
 {
-	return NULL;
+	return ERR_PTR(-ENODEV);
 }
 
 
 static inline struct regulator *__must_check
 devm_regulator_get_optional(struct device *dev, const char *id)
 {
-	return NULL;
+	return ERR_PTR(-ENODEV);
 }
 
 static inline void regulator_put(struct regulator *regulator)
-- 
1.7.9.5

Re: [PATCH] regulator: core: Return error in get optional stub

[Mark Brown]

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On Thu, Apr 17, 2014 at 11:55:24AM -0700, Tim Kryger wrote:
> Drivers that call regulator_get_optional are tolerant to the absence of
> that regulator.  By modifying the value returned from the stub function
> to match that seen when a regulator isn't present, callers can wrap the
> regulator logic with an IS_ERR based conditional even if they happen to
> call regulator_is_supported_voltage.  This improves efficiency as well
> as eliminates the possibility for a very subtle bug.

Applied, thanks.

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