[PATCH 0/4] simplify extcon_dev_register function.

[PATCH 0/4] simplify extcon_dev_register function.

[Bumwoo Lee]

It was modified to increase readability.

Bumwoo Lee (4):
  extcon: remove redundant null checking for class
  extcon: added extcon_alloc_cables to simplify extcon register function
  extcon: added extcon_alloc_muex to simplify extcon register function
  extcon: added extcon_alloc_groups to simplify extcon register function

 drivers/extcon/extcon.c | 286 ++++++++++++++++++++++------------------
 1 file changed, 160 insertions(+), 126 deletions(-)

-- 
2.35.1

[PATCH 1/4] extcon: remove redundant null checking for class

[Bumwoo Lee]

Create_extcon_class() is already Null checking.

Signed-off-by: Bumwoo Lee <bw365.lee@samsung.com>
---
 drivers/extcon/extcon.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
index e1c71359b605..adcf01132f70 100644
--- a/drivers/extcon/extcon.c
+++ b/drivers/extcon/extcon.c
@@ -1012,12 +1012,13 @@ ATTRIBUTE_GROUPS(extcon);
 
 static int create_extcon_class(void)
 {
-	if (!extcon_class) {
-		extcon_class = class_create(THIS_MODULE, "extcon");
-		if (IS_ERR(extcon_class))
-			return PTR_ERR(extcon_class);
-		extcon_class->dev_groups = extcon_groups;
-	}
+	if (extcon_class)
+		return 0;
+
+	extcon_class = class_create(THIS_MODULE, "extcon");
+	if (IS_ERR(extcon_class))
+		return PTR_ERR(extcon_class);
+	extcon_class->dev_groups = extcon_groups;
 
 	return 0;
 }
@@ -1088,11 +1089,9 @@ int extcon_dev_register(struct extcon_dev *edev)
 	int ret, index = 0;
 	static atomic_t edev_no = ATOMIC_INIT(-1);
 
-	if (!extcon_class) {
-		ret = create_extcon_class();
-		if (ret < 0)
-			return ret;
-	}
+	ret = create_extcon_class();
+	if (ret < 0)
+		return ret;
 
 	if (!edev || !edev->supported_cable)
 		return -EINVAL;
-- 
2.35.1

[PATCH 2/4] extcon: added extcon_alloc_cables to simplify extcon register function

[Bumwoo Lee]

The cable allocation part is functionalized from extcon_dev_register.

Signed-off-by: Bumwoo Lee <bw365.lee@samsung.com>
---
 drivers/extcon/extcon.c | 103 ++++++++++++++++++++++------------------
 1 file changed, 58 insertions(+), 45 deletions(-)

diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
index adcf01132f70..28058a1d2745 100644
--- a/drivers/extcon/extcon.c
+++ b/drivers/extcon/extcon.c
@@ -1070,6 +1070,61 @@ void extcon_dev_free(struct extcon_dev *edev)
 }
 EXPORT_SYMBOL_GPL(extcon_dev_free);
 
+/**
+ * extcon_alloc_cables() - alloc the cables for extcon device
+ * @edev:	extcon device which has cables
+ *
+ * Returns 0 if success or error number if fail.
+ */
+static int extcon_alloc_cables(struct extcon_dev *edev)
+{
+	int index;
+	char *str;
+	struct extcon_cable *cable;
+
+	if (!edev->max_supported)
+		return 0;
+
+	edev->cables = kcalloc(edev->max_supported,
+			       sizeof(struct extcon_cable),
+			       GFP_KERNEL);
+	if (!edev->cables)
+		return -ENOMEM;
+
+	for (index = 0; index < edev->max_supported; index++) {
+		cable = &edev->cables[index];
+
+		str = kasprintf(GFP_KERNEL, "cable.%d", index);
+		if (!str) {
+			for (index--; index >= 0; index--) {
+				cable = &edev->cables[index];
+				kfree(cable->attr_g.name);
+			}
+			return -ENOMEM;
+		}
+
+		cable->edev = edev;
+		cable->cable_index = index;
+		cable->attrs[0] = &cable->attr_name.attr;
+		cable->attrs[1] = &cable->attr_state.attr;
+		cable->attrs[2] = NULL;
+		cable->attr_g.name = str;
+		cable->attr_g.attrs = cable->attrs;
+
+		sysfs_attr_init(&cable->attr_name.attr);
+		cable->attr_name.attr.name = "name";
+		cable->attr_name.attr.mode = 0444;
+		cable->attr_name.show = cable_name_show;
+
+		sysfs_attr_init(&cable->attr_state.attr);
+		cable->attr_state.attr.name = "state";
+		cable->attr_state.attr.mode = 0444;
+		cable->attr_state.show = cable_state_show;
+	}
+
+	return 0;
+}
+
 /**
  * extcon_dev_register() - Register an new extcon device
  * @edev:	the extcon device to be registered
@@ -1117,50 +1172,8 @@ int extcon_dev_register(struct extcon_dev *edev)
 	dev_set_name(&edev->dev, "extcon%lu",
 			(unsigned long)atomic_inc_return(&edev_no));
 
-	if (edev->max_supported) {
-		char *str;
-		struct extcon_cable *cable;
-
-		edev->cables = kcalloc(edev->max_supported,
-				       sizeof(struct extcon_cable),
-				       GFP_KERNEL);
-		if (!edev->cables) {
-			ret = -ENOMEM;
-			goto err_sysfs_alloc;
-		}
-		for (index = 0; index < edev->max_supported; index++) {
-			cable = &edev->cables[index];
-
-			str = kasprintf(GFP_KERNEL, "cable.%d", index);
-			if (!str) {
-				for (index--; index >= 0; index--) {
-					cable = &edev->cables[index];
-					kfree(cable->attr_g.name);
-				}
-				ret = -ENOMEM;
-
-				goto err_alloc_cables;
-			}
-
-			cable->edev = edev;
-			cable->cable_index = index;
-			cable->attrs[0] = &cable->attr_name.attr;
-			cable->attrs[1] = &cable->attr_state.attr;
-			cable->attrs[2] = NULL;
-			cable->attr_g.name = str;
-			cable->attr_g.attrs = cable->attrs;
-
-			sysfs_attr_init(&cable->attr_name.attr);
-			cable->attr_name.attr.name = "name";
-			cable->attr_name.attr.mode = 0444;
-			cable->attr_name.show = cable_name_show;
-
-			sysfs_attr_init(&cable->attr_state.attr);
-			cable->attr_state.attr.name = "state";
-			cable->attr_state.attr.mode = 0444;
-			cable->attr_state.show = cable_state_show;
-		}
-	}
+	if (extcon_alloc_cables(edev))
+		goto err_alloc_cables;
 
 	if (edev->max_supported && edev->mutually_exclusive) {
 		char *name;
@@ -1282,7 +1295,7 @@ int extcon_dev_register(struct extcon_dev *edev)
 err_alloc_cables:
 	if (edev->max_supported)
 		kfree(edev->cables);
-err_sysfs_alloc:
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(extcon_dev_register);
-- 
2.35.1

[PATCH 3/4] extcon: added extcon_alloc_muex to simplify extcon register function

[Bumwoo Lee]

The mutual exclusive part is functionalized from extcon_dev_register.

Signed-off-by: Bumwoo Lee <bw365.lee@samsung.com>
---
 drivers/extcon/extcon.c | 105 ++++++++++++++++++++++------------------
 1 file changed, 57 insertions(+), 48 deletions(-)

diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
index 28058a1d2745..93cab4fe178e 100644
--- a/drivers/extcon/extcon.c
+++ b/drivers/extcon/extcon.c
@@ -1125,6 +1125,60 @@ static int extcon_alloc_cables(struct extcon_dev *edev)
 	return 0;
 }
 
+/**
+ * extcon_alloc_muex() - alloc the mutual exclusive for extcon device
+ * @edev:	extcon device
+ *
+ * Returns 0 if success or error number if fail.
+ */
+static int extcon_alloc_muex(struct extcon_dev *edev)
+{
+	char *name;
+	int index;
+
+	if (!(edev->max_supported && edev->mutually_exclusive))
+		return 0;
+
+	/* Count the size of mutually_exclusive array */
+	for (index = 0; edev->mutually_exclusive[index]; index++)
+		;
+
+	edev->attrs_muex = kcalloc(index + 1,
+				   sizeof(struct attribute *),
+				   GFP_KERNEL);
+	if (!edev->attrs_muex)
+		return -ENOMEM;
+
+	edev->d_attrs_muex = kcalloc(index,
+				     sizeof(struct device_attribute),
+				     GFP_KERNEL);
+	if (!edev->d_attrs_muex) {
+		kfree(edev->attrs_muex);
+		return -ENOMEM;
+	}
+
+	for (index = 0; edev->mutually_exclusive[index]; index++) {
+		name = kasprintf(GFP_KERNEL, "0x%x",
+				 edev->mutually_exclusive[index]);
+		if (!name) {
+			for (index--; index >= 0; index--)
+				kfree(edev->d_attrs_muex[index].attr.name);
+
+			kfree(edev->d_attrs_muex);
+			kfree(edev->attrs_muex);
+			return -ENOMEM;
+		}
+		sysfs_attr_init(&edev->d_attrs_muex[index].attr);
+		edev->d_attrs_muex[index].attr.name = name;
+		edev->d_attrs_muex[index].attr.mode = 0000;
+		edev->attrs_muex[index] = &edev->d_attrs_muex[index].attr;
+	}
+	edev->attr_g_muex.name = muex_name;
+	edev->attr_g_muex.attrs = edev->attrs_muex;
+
+	return 0;
+}
+
 /**
  * extcon_dev_register() - Register an new extcon device
  * @edev:	the extcon device to be registered
@@ -1175,53 +1229,8 @@ int extcon_dev_register(struct extcon_dev *edev)
 	if (extcon_alloc_cables(edev))
 		goto err_alloc_cables;
 
-	if (edev->max_supported && edev->mutually_exclusive) {
-		char *name;
-
-		/* Count the size of mutually_exclusive array */
-		for (index = 0; edev->mutually_exclusive[index]; index++)
-			;
-
-		edev->attrs_muex = kcalloc(index + 1,
-					   sizeof(struct attribute *),
-					   GFP_KERNEL);
-		if (!edev->attrs_muex) {
-			ret = -ENOMEM;
-			goto err_muex;
-		}
-
-		edev->d_attrs_muex = kcalloc(index,
-					     sizeof(struct device_attribute),
-					     GFP_KERNEL);
-		if (!edev->d_attrs_muex) {
-			ret = -ENOMEM;
-			kfree(edev->attrs_muex);
-			goto err_muex;
-		}
-
-		for (index = 0; edev->mutually_exclusive[index]; index++) {
-			name = kasprintf(GFP_KERNEL, "0x%x",
-					 edev->mutually_exclusive[index]);
-			if (!name) {
-				for (index--; index >= 0; index--) {
-					kfree(edev->d_attrs_muex[index].attr.
-					      name);
-				}
-				kfree(edev->d_attrs_muex);
-				kfree(edev->attrs_muex);
-				ret = -ENOMEM;
-				goto err_muex;
-			}
-			sysfs_attr_init(&edev->d_attrs_muex[index].attr);
-			edev->d_attrs_muex[index].attr.name = name;
-			edev->d_attrs_muex[index].attr.mode = 0000;
-			edev->attrs_muex[index] = &edev->d_attrs_muex[index]
-							.attr;
-		}
-		edev->attr_g_muex.name = muex_name;
-		edev->attr_g_muex.attrs = edev->attrs_muex;
-
-	}
+	if (extcon_alloc_muex(edev))
+		goto err_alloc_muex;
 
 	if (edev->max_supported) {
 		edev->extcon_dev_type.groups =
@@ -1289,7 +1298,7 @@ int extcon_dev_register(struct extcon_dev *edev)
 		kfree(edev->d_attrs_muex);
 		kfree(edev->attrs_muex);
 	}
-err_muex:
+err_alloc_muex:
 	for (index = 0; index < edev->max_supported; index++)
 		kfree(edev->cables[index].attr_g.name);
 err_alloc_cables:
-- 
2.35.1

[PATCH 4/4] extcon: added extcon_alloc_groups to simplify extcon register function

[Bumwoo Lee]

The alloc groups is functionalized from extcon_dev_register.

Signed-off-by: Bumwoo Lee <bw365.lee@samsung.com>
---
 drivers/extcon/extcon.c | 57 +++++++++++++++++++++++++----------------
 1 file changed, 35 insertions(+), 22 deletions(-)

diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
index 93cab4fe178e..9336d0d7589a 100644
--- a/drivers/extcon/extcon.c
+++ b/drivers/extcon/extcon.c
@@ -1179,6 +1179,39 @@ static int extcon_alloc_muex(struct extcon_dev *edev)
 	return 0;
 }
 
+/**
+ * extcon_alloc_groups() - alloc the groups for extcon device
+ * @edev:	extcon device
+ *
+ * Returns 0 if success or error number if fail.
+ */
+static int extcon_alloc_groups(struct extcon_dev *edev)
+{
+	int index;
+
+	if (!edev->max_supported)
+		return 0;
+
+	edev->extcon_dev_type.groups = kcalloc(edev->max_supported + 2,
+			sizeof(struct attribute_group *),
+			GFP_KERNEL);
+	if (!edev->extcon_dev_type.groups)
+		return -ENOMEM;
+
+	edev->extcon_dev_type.name = dev_name(&edev->dev);
+	edev->extcon_dev_type.release = dummy_sysfs_dev_release;
+
+	for (index = 0; index < edev->max_supported; index++)
+		edev->extcon_dev_type.groups[index] = &edev->cables[index].attr_g;
+
+	if (edev->mutually_exclusive)
+		edev->extcon_dev_type.groups[index] = &edev->attr_g_muex;
+
+	edev->dev.type = &edev->extcon_dev_type;
+
+	return 0;
+}
+
 /**
  * extcon_dev_register() - Register an new extcon device
  * @edev:	the extcon device to be registered
@@ -1232,28 +1265,8 @@ int extcon_dev_register(struct extcon_dev *edev)
 	if (extcon_alloc_muex(edev))
 		goto err_alloc_muex;
 
-	if (edev->max_supported) {
-		edev->extcon_dev_type.groups =
-			kcalloc(edev->max_supported + 2,
-				sizeof(struct attribute_group *),
-				GFP_KERNEL);
-		if (!edev->extcon_dev_type.groups) {
-			ret = -ENOMEM;
-			goto err_alloc_groups;
-		}
-
-		edev->extcon_dev_type.name = dev_name(&edev->dev);
-		edev->extcon_dev_type.release = dummy_sysfs_dev_release;
-
-		for (index = 0; index < edev->max_supported; index++)
-			edev->extcon_dev_type.groups[index] =
-				&edev->cables[index].attr_g;
-		if (edev->mutually_exclusive)
-			edev->extcon_dev_type.groups[index] =
-				&edev->attr_g_muex;
-
-		edev->dev.type = &edev->extcon_dev_type;
-	}
+	if (extcon_alloc_groups(edev))
+		goto err_alloc_groups;
 
 	spin_lock_init(&edev->lock);
 	if (edev->max_supported) {
-- 
2.35.1

RE: [PATCH 3/4] extcon: added extcon_alloc_muex to simplify extcon register function

[MyungJoo Ham]

>--------- Original Message ---------
>Sender : 이범우 <bw365.lee@samsung.com>Product S/W Lab(VD)/삼성전자
>Date : 2023-02-17 17:48 (GMT+9)
>Title : [PATCH 3/4] extcon: added extcon_alloc_muex to simplify extcon register function
> 
>The mutual exclusive part is functionalized from extcon_dev_register.
>
>Signed-off-by: Bumwoo Lee <bw365.lee@samsung.com>
>---
> drivers/extcon/extcon.c | 105 ++++++++++++++++++++++------------------
> 1 file changed, 57 insertions(+), 48 deletions(-)
>
>diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
>index 28058a1d2745..93cab4fe178e 100644
>--- a/drivers/extcon/extcon.c
>+++ b/drivers/extcon/extcon.c
>@@ -1125,6 +1125,60 @@ static int extcon_alloc_cables(struct extcon_dev *edev)
>         return 0;
> }
> 
...
>-                if (!edev->attrs_muex) {
>-                        ret = -ENOMEM;
>-                        goto err_muex;
>-                }
...
>+        if (extcon_alloc_muex(edev))
>+                goto err_alloc_muex;

It's not good.
You may return an uninitialized value or 0 when your new function has an error.

Cheers,
MyungJoo

RE: [PATCH 2/4] extcon: added extcon_alloc_cables to simplify extcon register function

[MyungJoo Ham]

>--------- Original Message ---------
>Sender : 이범우 <bw365.lee@samsung.com>Product S/W Lab(VD)/삼성전자
>Date : 2023-02-17 17:48 (GMT+9)
>Title : [PATCH 2/4] extcon: added extcon_alloc_cables to simplify extcon register function
> 
>The cable allocation part is functionalized from extcon_dev_register.
>
>Signed-off-by: Bumwoo Lee <bw365.lee@samsung.com>

...

>+        if (extcon_alloc_cables(edev))
>+                goto err_alloc_cables;
> 

You are abandoning error return values, here.
Please return appropriate error codes.

Cheers,
MyungJoo

RE: [PATCH 2/4] extcon: added extcon_alloc_cables to simplify extcon register function

[Bumwoo Lee]

I Got it.

I will prepare new patch for return value.

Thank for your comment.

Regards,
Bumwoo.
-----Original Message-----
From: MyungJoo Ham <myungjoo.ham@samsung.com> 
Sent: Monday, February 20, 2023 1:39 PM
To: Bumwoo Lee <bw365.lee@samsung.com>; Chanwoo Choi <cw00.choi@samsung.com>; linux-kernel@vger.kernel.org
Subject: RE: [PATCH 2/4] extcon: added extcon_alloc_cables to simplify extcon register function

>--------- Original Message ---------
>Sender : 이범우 <bw365.lee@samsung.com>Product S/W Lab(VD)/삼성전자 Date : 
>2023-02-17 17:48 (GMT+9) Title : [PATCH 2/4] extcon: added 
>extcon_alloc_cables to simplify extcon register function
> 
>The cable allocation part is functionalized from extcon_dev_register.
>
>Signed-off-by: Bumwoo Lee <bw365.lee@samsung.com>

...

>+        if (extcon_alloc_cables(edev))
>+                goto err_alloc_cables;
> 

You are abandoning error return values, here.
Please return appropriate error codes.

Cheers,
MyungJoo