[PATCHv2 for v4.19-stable 0/6] reset: make optional functions

[PATCHv2 for v4.19-stable 0/6] reset: make optional functions

[Dinh Nguyen]

Hi Greg/Sasha:

Please apply this series to v4.9.y stable tree. The reason is that v4.9-stable
branch has this patch for stmmac ethernet driver:

"6f37f7b62baa net: stmmac: socfpga: add additional ocp reset line for
Stratix10"

This patch calls devm_reset_control_get_optional(). This call ultimately
fails without this reset patch, becuase the call to
devm_reset_control_get_optional() is returning an error code, which causes the
ethernet driver to fail to load. This patch fixes the call to *_get_optional_* 
in that any call to the reset driver with *_optional_* will return 0 instead of
an error value.

Patches 2-6 are needed as well because those patches fix patch 1/6.

Thanks..

Dinh

Heiner Kallweit (1):
  reset: core: fix reset_control_put

Masahiro Yamada (2):
  reset: make device_reset_optional() really optional
  reset: remove remaining WARN_ON() in <linux/reset.h>

Philipp Zabel (2):
  reset: fix optional reset_control_get stubs to return NULL
  reset: add exported __reset_control_get, return NULL if optional

Ramiro Oliveira (1):
  reset: make optional functions really optional

 drivers/reset/core.c  | 79 +++++++++++++++++++++++++++----------
 include/linux/reset.h | 92 +++++++++++++++++++++----------------------
 2 files changed, 104 insertions(+), 67 deletions(-)

-- 
2.17.1

[PATCHv2 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>
---
 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

[PATCHv2 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

[PATCHv2 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

[PATCHv2 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

[PATCHv2 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

[PATCHv2 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: [PATCHv2 for v4.19-stable 0/6] reset: make optional functions

[Greg KH]

On Tue, Dec 04, 2018 at 09:34:42AM -0600, Dinh Nguyen wrote:
> Hi Greg/Sasha:
> 
> Please apply this series to v4.9.y stable tree. The reason is that v4.9-stable
> branch has this patch for stmmac ethernet driver:

"4.9" or "4.19" like your subject lines say?  :)

Re: [PATCHv2 for v4.19-stable 0/6] reset: make optional functions

[Greg KH]

On Tue, Dec 04, 2018 at 09:34:42AM -0600, Dinh Nguyen wrote:
> Hi Greg/Sasha:
> 
> Please apply this series to v4.9.y stable tree. The reason is that v4.9-stable
> branch has this patch for stmmac ethernet driver:
> 
> "6f37f7b62baa net: stmmac: socfpga: add additional ocp reset line for
> Stratix10"

How about we just revert this patch?  It seems to be causing too many
problems to require all of these "core" patches to be added.  Would that
resolve the issue?

thanks,

greg k-h

Re: [PATCHv2 for v4.19-stable 0/6] reset: make optional functions

[Dinh Nguyen]

On 12/4/18 9:45 AM, Greg KH wrote:
> On Tue, Dec 04, 2018 at 09:34:42AM -0600, Dinh Nguyen wrote:
>> Hi Greg/Sasha:
>>
>> Please apply this series to v4.9.y stable tree. The reason is that v4.9-stable
>> branch has this patch for stmmac ethernet driver:
>>
>> "6f37f7b62baa net: stmmac: socfpga: add additional ocp reset line for
>> Stratix10"
> 
> How about we just revert this patch?  It seems to be causing too many
> problems to require all of these "core" patches to be added.  Would that
> resolve the issue?
> 

Sorry about that, the subject line should be "for v4.9-stable".

I'm fine with reverting the patch. However, I can see that there are
other drivers calling devm_reset_control_get_optional() where these
patches may be needed.

Dinh

Re: [PATCHv2 for v4.19-stable 0/6] reset: make optional functions

[Greg KH]

On Tue, Dec 04, 2018 at 11:27:48AM -0600, Dinh Nguyen wrote:
> 
> 
> On 12/4/18 9:45 AM, Greg KH wrote:
> > On Tue, Dec 04, 2018 at 09:34:42AM -0600, Dinh Nguyen wrote:
> >> Hi Greg/Sasha:
> >>
> >> Please apply this series to v4.9.y stable tree. The reason is that v4.9-stable
> >> branch has this patch for stmmac ethernet driver:
> >>
> >> "6f37f7b62baa net: stmmac: socfpga: add additional ocp reset line for
> >> Stratix10"
> > 
> > How about we just revert this patch?  It seems to be causing too many
> > problems to require all of these "core" patches to be added.  Would that
> > resolve the issue?
> > 
> 
> Sorry about that, the subject line should be "for v4.9-stable".
> 
> I'm fine with reverting the patch. However, I can see that there are
> other drivers calling devm_reset_control_get_optional() where these
> patches may be needed.

Ok, this will probably be best overall, so I've queued them up now.

Also 2 of these needed to go into 4.14.y, so I put them there too.

Next time, when you send backports that you had to modify, can you
please sign-off on the patches as well?

thanks,

greg k-h

Re: [PATCHv2 for v4.19-stable 0/6] reset: make optional functions

[Dinh Nguyen]

On 12/6/18 5:01 AM, Greg KH wrote:
> On Tue, Dec 04, 2018 at 11:27:48AM -0600, Dinh Nguyen wrote:
>>
>>
>> On 12/4/18 9:45 AM, Greg KH wrote:
>>> On Tue, Dec 04, 2018 at 09:34:42AM -0600, Dinh Nguyen wrote:
>>>> Hi Greg/Sasha:
>>>>
>>>> Please apply this series to v4.9.y stable tree. The reason is that v4.9-stable
>>>> branch has this patch for stmmac ethernet driver:
>>>>
>>>> "6f37f7b62baa net: stmmac: socfpga: add additional ocp reset line for
>>>> Stratix10"
>>>
>>> How about we just revert this patch?  It seems to be causing too many
>>> problems to require all of these "core" patches to be added.  Would that
>>> resolve the issue?
>>>
>>
>> Sorry about that, the subject line should be "for v4.9-stable".
>>
>> I'm fine with reverting the patch. However, I can see that there are
>> other drivers calling devm_reset_control_get_optional() where these
>> patches may be needed.
> 
> Ok, this will probably be best overall, so I've queued them up now.
> 
> Also 2 of these needed to go into 4.14.y, so I put them there too.
> 
> Next time, when you send backports that you had to modify, can you
> please sign-off on the patches as well?
> 

Will do, thanks!

Dinh