[PATCH for v4.19-stable 1/6] reset: make optional functions really optional

[PATCH for v4.19-stable 1/6] reset: make optional functions really optional

[Dinh Nguyen]

From: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>

commit bb475230b8e59a547ab66ac3b02572df21a580e9 upstream.

The *_get_optional_* functions weren't really optional so this patch
makes them really optional.

These *_get_optional_* functions will now return NULL instead of an error
if no matching reset phandle is found in the DT, and all the
reset_control_* functions now accept NULL rstc pointers.

Signed-off-by: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
Please apply to v4.9.y stable tree.
---
 drivers/reset/core.c  | 48 +++++++++++++++++++++++++++++++++----------
 include/linux/reset.h | 45 +++++++++++++++++++++++-----------------
 2 files changed, 63 insertions(+), 30 deletions(-)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index b8ae1dbd4c17..75821417b799 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -135,11 +135,16 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
  * @rstc: reset controller
  *
  * Calling this on a shared reset controller is an error.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
  */
 int reset_control_reset(struct reset_control *rstc)
 {
-	if (WARN_ON(IS_ERR_OR_NULL(rstc)) ||
-	    WARN_ON(rstc->shared))
+	if (!rstc)
+		return 0;
+
+	if (WARN_ON(IS_ERR(rstc)))
 		return -EINVAL;
 
 	if (rstc->rcdev->ops->reset)
@@ -159,10 +164,16 @@ EXPORT_SYMBOL_GPL(reset_control_reset);
  *
  * For shared reset controls a driver cannot expect the hw's registers and
  * internal state to be reset, but must be prepared for this to happen.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
  */
 int reset_control_assert(struct reset_control *rstc)
 {
-	if (WARN_ON(IS_ERR_OR_NULL(rstc)))
+	if (!rstc)
+		return 0;
+
+	if (WARN_ON(IS_ERR(rstc)))
 		return -EINVAL;
 
 	if (!rstc->rcdev->ops->assert)
@@ -185,10 +196,16 @@ EXPORT_SYMBOL_GPL(reset_control_assert);
  * @rstc: reset controller
  *
  * After calling this function, the reset is guaranteed to be deasserted.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
  */
 int reset_control_deassert(struct reset_control *rstc)
 {
-	if (WARN_ON(IS_ERR_OR_NULL(rstc)))
+	if (!rstc)
+		return 0;
+
+	if (WARN_ON(IS_ERR(rstc)))
 		return -EINVAL;
 
 	if (!rstc->rcdev->ops->deassert)
@@ -206,12 +223,15 @@ EXPORT_SYMBOL_GPL(reset_control_deassert);
 /**
  * reset_control_status - returns a negative errno if not supported, a
  * positive value if the reset line is asserted, or zero if the reset
- * line is not asserted.
+ * line is not asserted or if the desc is NULL (optional reset).
  * @rstc: reset controller
  */
 int reset_control_status(struct reset_control *rstc)
 {
-	if (WARN_ON(IS_ERR_OR_NULL(rstc)))
+	if (!rstc)
+		return 0;
+
+	if (WARN_ON(IS_ERR(rstc)))
 		return -EINVAL;
 
 	if (rstc->rcdev->ops->status)
@@ -268,7 +288,8 @@ static void __reset_control_put(struct reset_control *rstc)
 }
 
 struct reset_control *__of_reset_control_get(struct device_node *node,
-				     const char *id, int index, int shared)
+				     const char *id, int index, bool shared,
+				     bool optional)
 {
 	struct reset_control *rstc;
 	struct reset_controller_dev *r, *rcdev;
@@ -282,14 +303,18 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
 	if (id) {
 		index = of_property_match_string(node,
 						 "reset-names", id);
+		if (index == -EILSEQ)
+			return ERR_PTR(index);
 		if (index < 0)
-			return ERR_PTR(-ENOENT);
+			return optional ? NULL : ERR_PTR(-ENOENT);
 	}
 
 	ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",
 					 index, &args);
-	if (ret)
+	if (ret == -EINVAL)
 		return ERR_PTR(ret);
+	if (ret)
+		return optional ? NULL : ERR_PTR(ret);
 
 	mutex_lock(&reset_list_mutex);
 	rcdev = NULL;
@@ -348,7 +373,8 @@ static void devm_reset_control_release(struct device *dev, void *res)
 }
 
 struct reset_control *__devm_reset_control_get(struct device *dev,
-				     const char *id, int index, int shared)
+				     const char *id, int index, bool shared,
+				     bool optional)
 {
 	struct reset_control **ptr, *rstc;
 
@@ -358,7 +384,7 @@ struct reset_control *__devm_reset_control_get(struct device *dev,
 		return ERR_PTR(-ENOMEM);
 
 	rstc = __of_reset_control_get(dev ? dev->of_node : NULL,
-				      id, index, shared);
+				      id, index, shared, optional);
 	if (!IS_ERR(rstc)) {
 		*ptr = rstc;
 		devres_add(dev, ptr);
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 5daff15722d3..86b4ed75359e 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -13,10 +13,12 @@ int reset_control_deassert(struct reset_control *rstc);
 int reset_control_status(struct reset_control *rstc);
 
 struct reset_control *__of_reset_control_get(struct device_node *node,
-				     const char *id, int index, int shared);
+				     const char *id, int index, bool shared,
+				     bool optional);
 void reset_control_put(struct reset_control *rstc);
 struct reset_control *__devm_reset_control_get(struct device *dev,
-				     const char *id, int index, int shared);
+				     const char *id, int index, bool shared,
+				     bool optional);
 
 int __must_check device_reset(struct device *dev);
 
@@ -69,14 +71,15 @@ static inline int device_reset_optional(struct device *dev)
 
 static inline struct reset_control *__of_reset_control_get(
 					struct device_node *node,
-					const char *id, int index, int shared)
+					const char *id, int index, bool shared,
+					bool optional)
 {
 	return ERR_PTR(-ENOTSUPP);
 }
 
 static inline struct reset_control *__devm_reset_control_get(
-					struct device *dev,
-					const char *id, int index, int shared)
+					struct device *dev, const char *id,
+					int index, bool shared, bool optional)
 {
 	return ERR_PTR(-ENOTSUPP);
 }
@@ -104,7 +107,8 @@ __must_check reset_control_get_exclusive(struct device *dev, const char *id)
 #ifndef CONFIG_RESET_CONTROLLER
 	WARN_ON(1);
 #endif
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
+	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, false,
+									false);
 }
 
 /**
@@ -132,19 +136,22 @@ __must_check reset_control_get_exclusive(struct device *dev, const char *id)
 static inline struct reset_control *reset_control_get_shared(
 					struct device *dev, const char *id)
 {
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 1);
+	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, true,
+									false);
 }
 
 static inline struct reset_control *reset_control_get_optional_exclusive(
 					struct device *dev, const char *id)
 {
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
+	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, false,
+									true);
 }
 
 static inline struct reset_control *reset_control_get_optional_shared(
 					struct device *dev, const char *id)
 {
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 1);
+	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, true,
+									true);
 }
 
 /**
@@ -160,7 +167,7 @@ static inline struct reset_control *reset_control_get_optional_shared(
 static inline struct reset_control *of_reset_control_get_exclusive(
 				struct device_node *node, const char *id)
 {
-	return __of_reset_control_get(node, id, 0, 0);
+	return __of_reset_control_get(node, id, 0, false, false);
 }
 
 /**
@@ -185,7 +192,7 @@ static inline struct reset_control *of_reset_control_get_exclusive(
 static inline struct reset_control *of_reset_control_get_shared(
 				struct device_node *node, const char *id)
 {
-	return __of_reset_control_get(node, id, 0, 1);
+	return __of_reset_control_get(node, id, 0, true, false);
 }
 
 /**
@@ -202,7 +209,7 @@ static inline struct reset_control *of_reset_control_get_shared(
 static inline struct reset_control *of_reset_control_get_exclusive_by_index(
 					struct device_node *node, int index)
 {
-	return __of_reset_control_get(node, NULL, index, 0);
+	return __of_reset_control_get(node, NULL, index, false, false);
 }
 
 /**
@@ -230,7 +237,7 @@ static inline struct reset_control *of_reset_control_get_exclusive_by_index(
 static inline struct reset_control *of_reset_control_get_shared_by_index(
 					struct device_node *node, int index)
 {
-	return __of_reset_control_get(node, NULL, index, 1);
+	return __of_reset_control_get(node, NULL, index, true, false);
 }
 
 /**
@@ -252,7 +259,7 @@ __must_check devm_reset_control_get_exclusive(struct device *dev,
 #ifndef CONFIG_RESET_CONTROLLER
 	WARN_ON(1);
 #endif
-	return __devm_reset_control_get(dev, id, 0, 0);
+	return __devm_reset_control_get(dev, id, 0, false, false);
 }
 
 /**
@@ -267,19 +274,19 @@ __must_check devm_reset_control_get_exclusive(struct device *dev,
 static inline struct reset_control *devm_reset_control_get_shared(
 					struct device *dev, const char *id)
 {
-	return __devm_reset_control_get(dev, id, 0, 1);
+	return __devm_reset_control_get(dev, id, 0, true, false);
 }
 
 static inline struct reset_control *devm_reset_control_get_optional_exclusive(
 					struct device *dev, const char *id)
 {
-	return __devm_reset_control_get(dev, id, 0, 0);
+	return __devm_reset_control_get(dev, id, 0, false, true);
 }
 
 static inline struct reset_control *devm_reset_control_get_optional_shared(
 					struct device *dev, const char *id)
 {
-	return __devm_reset_control_get(dev, id, 0, 1);
+	return __devm_reset_control_get(dev, id, 0, true, true);
 }
 
 /**
@@ -297,7 +304,7 @@ static inline struct reset_control *devm_reset_control_get_optional_shared(
 static inline struct reset_control *
 devm_reset_control_get_exclusive_by_index(struct device *dev, int index)
 {
-	return __devm_reset_control_get(dev, NULL, index, 0);
+	return __devm_reset_control_get(dev, NULL, index, false, false);
 }
 
 /**
@@ -313,7 +320,7 @@ devm_reset_control_get_exclusive_by_index(struct device *dev, int index)
 static inline struct reset_control *
 devm_reset_control_get_shared_by_index(struct device *dev, int index)
 {
-	return __devm_reset_control_get(dev, NULL, index, 1);
+	return __devm_reset_control_get(dev, NULL, index, true, false);
 }
 
 /*
-- 
2.17.1

[PATCH for v4.19-stable 2/6] reset: core: fix reset_control_put

[Dinh Nguyen]

From: Heiner Kallweit <hkallweit1@gmail.com>

commit 4891486fb2c80eaf3bb0f9eb065d15ecd357702f upstream.

Commit "reset: make optional functions really optional" missed to
adjust one check in reset_control_put, causing a NULL pointer
access for optional resets.

Fixes: bb475230b8e5 "reset: make optional functions really optional"
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 drivers/reset/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 75821417b799..f62f57ebc45a 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -358,7 +358,7 @@ EXPORT_SYMBOL_GPL(__of_reset_control_get);
 
 void reset_control_put(struct reset_control *rstc)
 {
-	if (IS_ERR(rstc))
+	if (IS_ERR_OR_NULL(rstc))
 		return;
 
 	mutex_lock(&reset_list_mutex);
-- 
2.17.1

[PATCH for v4.19-stable 3/6] reset: fix optional reset_control_get stubs to return NULL

[Dinh Nguyen]

From: Philipp Zabel <p.zabel@pengutronix.de>

commit 0ca10b60ceeb5372da01798ca68c116ae45a6eb6 upstream.

When RESET_CONTROLLER is not enabled, the optional reset_control_get
stubs should now also return NULL.

Since it is now valid for reset_control_assert/deassert/reset/status/put
to be called unconditionally, with NULL as an argument for optional
resets, the stubs are not allowed to warn anymore.

Fixes: bb475230b8e5 ("reset: make optional functions really optional")
Reported-by: Andrzej Hajda <a.hajda@samsung.com>
Tested-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Cc: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 include/linux/reset.h | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/include/linux/reset.h b/include/linux/reset.h
index 86b4ed75359e..96fb139bdd08 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -31,31 +31,26 @@ static inline int device_reset_optional(struct device *dev)
 
 static inline int reset_control_reset(struct reset_control *rstc)
 {
-	WARN_ON(1);
 	return 0;
 }
 
 static inline int reset_control_assert(struct reset_control *rstc)
 {
-	WARN_ON(1);
 	return 0;
 }
 
 static inline int reset_control_deassert(struct reset_control *rstc)
 {
-	WARN_ON(1);
 	return 0;
 }
 
 static inline int reset_control_status(struct reset_control *rstc)
 {
-	WARN_ON(1);
 	return 0;
 }
 
 static inline void reset_control_put(struct reset_control *rstc)
 {
-	WARN_ON(1);
 }
 
 static inline int __must_check device_reset(struct device *dev)
@@ -74,14 +69,14 @@ static inline struct reset_control *__of_reset_control_get(
 					const char *id, int index, bool shared,
 					bool optional)
 {
-	return ERR_PTR(-ENOTSUPP);
+	return optional ? NULL : ERR_PTR(-ENOTSUPP);
 }
 
 static inline struct reset_control *__devm_reset_control_get(
 					struct device *dev, const char *id,
 					int index, bool shared, bool optional)
 {
-	return ERR_PTR(-ENOTSUPP);
+	return optional ? NULL : ERR_PTR(-ENOTSUPP);
 }
 
 #endif /* CONFIG_RESET_CONTROLLER */
-- 
2.17.1

[PATCH for v4.19-stable 4/6] reset: add exported __reset_control_get, return NULL if optional

[Dinh Nguyen]

From: Philipp Zabel <p.zabel@pengutronix.de>

commit 62e24c5775ecb387a3eb33701378ccfa6dbc98ee upstream.

Rename the internal __reset_control_get/put functions to
__reset_control_get/put_internal and add an exported
__reset_control_get equivalent to __of_reset_control_get
that takes a struct device parameter.
This avoids the confusing call to __of_reset_control_get in
the non-DT case and fixes the devm_reset_control_get_optional
function to return NULL if RESET_CONTROLLER is enabled but
dev->of_node == NULL.

Fixes: bb475230b8e5 ("reset: make optional functions really optional")
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 drivers/reset/core.c  | 22 ++++++++++++++++------
 include/linux/reset.h | 22 ++++++++++++++--------
 2 files changed, 30 insertions(+), 14 deletions(-)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index f62f57ebc45a..e8cb31616c3e 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -241,7 +241,7 @@ int reset_control_status(struct reset_control *rstc)
 }
 EXPORT_SYMBOL_GPL(reset_control_status);
 
-static struct reset_control *__reset_control_get(
+static struct reset_control *__reset_control_get_internal(
 				struct reset_controller_dev *rcdev,
 				unsigned int index, int shared)
 {
@@ -274,7 +274,7 @@ static struct reset_control *__reset_control_get(
 	return rstc;
 }
 
-static void __reset_control_put(struct reset_control *rstc)
+static void __reset_control_put_internal(struct reset_control *rstc)
 {
 	lockdep_assert_held(&reset_list_mutex);
 
@@ -343,7 +343,7 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
 	}
 
 	/* reset_list_mutex also protects the rcdev's reset_control list */
-	rstc = __reset_control_get(rcdev, rstc_id, shared);
+	rstc = __reset_control_get_internal(rcdev, rstc_id, shared);
 
 	mutex_unlock(&reset_list_mutex);
 
@@ -351,6 +351,17 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
 }
 EXPORT_SYMBOL_GPL(__of_reset_control_get);
 
+struct reset_control *__reset_control_get(struct device *dev, const char *id,
+					  int index, bool shared, bool optional)
+{
+	if (dev->of_node)
+		return __of_reset_control_get(dev->of_node, id, index, shared,
+					      optional);
+
+	return optional ? NULL : ERR_PTR(-EINVAL);
+}
+EXPORT_SYMBOL_GPL(__reset_control_get);
+
 /**
  * reset_control_put - free the reset controller
  * @rstc: reset controller
@@ -362,7 +373,7 @@ void reset_control_put(struct reset_control *rstc)
 		return;
 
 	mutex_lock(&reset_list_mutex);
-	__reset_control_put(rstc);
+	__reset_control_put_internal(rstc);
 	mutex_unlock(&reset_list_mutex);
 }
 EXPORT_SYMBOL_GPL(reset_control_put);
@@ -383,8 +394,7 @@ struct reset_control *__devm_reset_control_get(struct device *dev,
 	if (!ptr)
 		return ERR_PTR(-ENOMEM);
 
-	rstc = __of_reset_control_get(dev ? dev->of_node : NULL,
-				      id, index, shared, optional);
+	rstc = __reset_control_get(dev, id, index, shared, optional);
 	if (!IS_ERR(rstc)) {
 		*ptr = rstc;
 		devres_add(dev, ptr);
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 96fb139bdd08..13d8681210d5 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -15,6 +15,9 @@ int reset_control_status(struct reset_control *rstc);
 struct reset_control *__of_reset_control_get(struct device_node *node,
 				     const char *id, int index, bool shared,
 				     bool optional);
+struct reset_control *__reset_control_get(struct device *dev, const char *id,
+					  int index, bool shared,
+					  bool optional);
 void reset_control_put(struct reset_control *rstc);
 struct reset_control *__devm_reset_control_get(struct device *dev,
 				     const char *id, int index, bool shared,
@@ -72,6 +75,13 @@ static inline struct reset_control *__of_reset_control_get(
 	return optional ? NULL : ERR_PTR(-ENOTSUPP);
 }
 
+static inline struct reset_control *__reset_control_get(
+					struct device *dev, const char *id,
+					int index, bool shared, bool optional)
+{
+	return optional ? NULL : ERR_PTR(-ENOTSUPP);
+}
+
 static inline struct reset_control *__devm_reset_control_get(
 					struct device *dev, const char *id,
 					int index, bool shared, bool optional)
@@ -102,8 +112,7 @@ __must_check reset_control_get_exclusive(struct device *dev, const char *id)
 #ifndef CONFIG_RESET_CONTROLLER
 	WARN_ON(1);
 #endif
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, false,
-									false);
+	return __reset_control_get(dev, id, 0, false, false);
 }
 
 /**
@@ -131,22 +140,19 @@ __must_check reset_control_get_exclusive(struct device *dev, const char *id)
 static inline struct reset_control *reset_control_get_shared(
 					struct device *dev, const char *id)
 {
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, true,
-									false);
+	return __reset_control_get(dev, id, 0, true, false);
 }
 
 static inline struct reset_control *reset_control_get_optional_exclusive(
 					struct device *dev, const char *id)
 {
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, false,
-									true);
+	return __reset_control_get(dev, id, 0, false, true);
 }
 
 static inline struct reset_control *reset_control_get_optional_shared(
 					struct device *dev, const char *id)
 {
-	return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, true,
-									true);
+	return __reset_control_get(dev, id, 0, true, true);
 }
 
 /**
-- 
2.17.1

[PATCH for v4.19-stable 5/6] reset: make device_reset_optional() really optional

[Dinh Nguyen]

From: Masahiro Yamada <yamada.masahiro@socionext.com>

commit 1554bbd4ad401b7f0f916c0891874111c10befe5 upstream.

Commit bb475230b8e5 ("reset: make optional functions really optional")
converted *_get_optional* functions, but device_reset_optional() was
left behind.  Convert it in the same way.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 drivers/reset/core.c  |  9 +++++----
 include/linux/reset.h | 28 +++++++++++++---------------
 2 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index e8cb31616c3e..188205a55261 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -410,17 +410,18 @@ EXPORT_SYMBOL_GPL(__devm_reset_control_get);
  * device_reset - find reset controller associated with the device
  *                and perform reset
  * @dev: device to be reset by the controller
+ * @optional: whether it is optional to reset the device
  *
- * Convenience wrapper for reset_control_get() and reset_control_reset().
+ * Convenience wrapper for __reset_control_get() and reset_control_reset().
  * This is useful for the common case of devices with single, dedicated reset
  * lines.
  */
-int device_reset(struct device *dev)
+int __device_reset(struct device *dev, bool optional)
 {
 	struct reset_control *rstc;
 	int ret;
 
-	rstc = reset_control_get(dev, NULL);
+	rstc = __reset_control_get(dev, NULL, 0, 0, optional);
 	if (IS_ERR(rstc))
 		return PTR_ERR(rstc);
 
@@ -430,4 +431,4 @@ int device_reset(struct device *dev)
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(device_reset);
+EXPORT_SYMBOL_GPL(__device_reset);
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 13d8681210d5..61a0dda3f981 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -19,17 +19,11 @@ struct reset_control *__reset_control_get(struct device *dev, const char *id,
 					  int index, bool shared,
 					  bool optional);
 void reset_control_put(struct reset_control *rstc);
+int __device_reset(struct device *dev, bool optional);
 struct reset_control *__devm_reset_control_get(struct device *dev,
 				     const char *id, int index, bool shared,
 				     bool optional);
 
-int __must_check device_reset(struct device *dev);
-
-static inline int device_reset_optional(struct device *dev)
-{
-	return device_reset(dev);
-}
-
 #else
 
 static inline int reset_control_reset(struct reset_control *rstc)
@@ -56,15 +50,9 @@ static inline void reset_control_put(struct reset_control *rstc)
 {
 }
 
-static inline int __must_check device_reset(struct device *dev)
+static inline int __device_reset(struct device *dev, bool optional)
 {
-	WARN_ON(1);
-	return -ENOTSUPP;
-}
-
-static inline int device_reset_optional(struct device *dev)
-{
-	return -ENOTSUPP;
+	return optional ? 0 : -ENOTSUPP;
 }
 
 static inline struct reset_control *__of_reset_control_get(
@@ -91,6 +79,16 @@ static inline struct reset_control *__devm_reset_control_get(
 
 #endif /* CONFIG_RESET_CONTROLLER */
 
+static inline int __must_check device_reset(struct device *dev)
+{
+	return __device_reset(dev, false);
+}
+
+static inline int device_reset_optional(struct device *dev)
+{
+	return __device_reset(dev, true);
+}
+
 /**
  * reset_control_get_exclusive - Lookup and obtain an exclusive reference
  *                               to a reset controller.
-- 
2.17.1

[PATCH for v4.19-stable 6/6] reset: remove remaining WARN_ON() in <linux/reset.h>

[Dinh Nguyen]

From: Masahiro Yamada <yamada.masahiro@socionext.com>

commit bb6c7768385b200063a14d6615cc1246c3d00760 upstream.

Commit bb475230b8e5 ("reset: make optional functions really optional")
gave a new meaning to _get_optional variants.

The differentiation by WARN_ON() is not needed any more.  We already
have inconsistency about this; (devm_)reset_control_get_exclusive()
has WARN_ON() check, but of_reset_control_get_exclusive() does not.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 include/linux/reset.h | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/include/linux/reset.h b/include/linux/reset.h
index 61a0dda3f981..7e99690dbc81 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -107,9 +107,6 @@ static inline int device_reset_optional(struct device *dev)
 static inline struct reset_control *
 __must_check reset_control_get_exclusive(struct device *dev, const char *id)
 {
-#ifndef CONFIG_RESET_CONTROLLER
-	WARN_ON(1);
-#endif
 	return __reset_control_get(dev, id, 0, false, false);
 }
 
@@ -255,9 +252,6 @@ static inline struct reset_control *
 __must_check devm_reset_control_get_exclusive(struct device *dev,
 					      const char *id)
 {
-#ifndef CONFIG_RESET_CONTROLLER
-	WARN_ON(1);
-#endif
 	return __devm_reset_control_get(dev, id, 0, false, false);
 }
 
-- 
2.17.1

Re: [PATCH for v4.19-stable 1/6] reset: make optional functions really optional

[Greg KH]

On Mon, Dec 03, 2018 at 03:42:09PM -0600, Dinh Nguyen wrote:
> From: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
> 
> commit bb475230b8e59a547ab66ac3b02572df21a580e9 upstream.
> 
> The *_get_optional_* functions weren't really optional so this patch
> makes them really optional.
> 
> These *_get_optional_* functions will now return NULL instead of an error
> if no matching reset phandle is found in the DT, and all the
> reset_control_* functions now accept NULL rstc pointers.
> 
> Signed-off-by: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> ---
> Please apply to v4.9.y stable tree.

Why is this patch series needed in 4.9?  You haven't provided any
justification here :(

thanks,

greg k-h