[PATCH v2 0/6] ACPI: dock: code hygiene

[PATCH v2 0/6] ACPI: dock: code hygiene

[Alex Chiang]

This is v2 of a modest attempt to clean up the dock driver.

As before, compile tested only, since I don't have any machines
that provide _DCK.

Thanks.
/ac

v1 -> v2:
	- changed how we add platform device data, based on Shaohua Li's
	  review

---

Alex Chiang (6):
      ACPI: dock: clean up error handling paths in dock_add()
      ACPI: dock: combine add|alloc_dock_dependent_device
      ACPI: dock: remove global 'dock_device_name'
      ACPI: dock: dock_add - hoist up platform_device_register_simple()
      ACPI: dock: add struct dock_station * directly to platform device data
      ACPI: dock: minor whitespace and style cleanups


 drivers/acpi/dock.c |  272 ++++++++++++++++++++-------------------------------
 1 files changed, 104 insertions(+), 168 deletions(-)

[PATCH v2 1/6] ACPI: dock: clean up error handling paths in dock_add()

[Alex Chiang]

Remove some copy/paste code in our error handling paths, which makes
the function smaller and slightly easier to read.

Signed-off-by: Alex Chiang <achiang@hp.com>
---

 drivers/acpi/dock.c |   75 +++++++++++++++++++--------------------------------
 1 files changed, 28 insertions(+), 47 deletions(-)

diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index 7338b6a..642c7dd 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -968,11 +968,9 @@ static int dock_add(acpi_handle handle)
 		platform_device_register_simple(dock_device_name,
 			dock_station_count, NULL, 0);
 	dock_device = dock_station->dock_device;
-	if (IS_ERR(dock_device)) {
-		kfree(dock_station);
-		dock_station = NULL;
-		return PTR_ERR(dock_device);
-	}
+	ret = IS_ERR(dock_device) ? PTR_ERR(dock_device) : 0;
+	if (ret)
+		goto out;
 	platform_device_add_data(dock_device, &dock_station,
 		sizeof(struct dock_station *));
 
@@ -987,46 +985,24 @@ static int dock_add(acpi_handle handle)
 		dock_station->flags |= DOCK_IS_BAT;
 
 	ret = device_create_file(&dock_device->dev, &dev_attr_docked);
-	if (ret) {
-		printk(KERN_ERR "Error %d adding sysfs file\n", ret);
-		platform_device_unregister(dock_device);
-		kfree(dock_station);
-		dock_station = NULL;
-		return ret;
-	}
+	if (ret)
+		goto err_unregister;
+
 	ret = device_create_file(&dock_device->dev, &dev_attr_undock);
-	if (ret) {
-		printk(KERN_ERR "Error %d adding sysfs file\n", ret);
-		device_remove_file(&dock_device->dev, &dev_attr_docked);
-		platform_device_unregister(dock_device);
-		kfree(dock_station);
-		dock_station = NULL;
-		return ret;
-	}
+	if (ret)
+		goto err_unregister1;
+
 	ret = device_create_file(&dock_device->dev, &dev_attr_uid);
-	if (ret) {
-		printk(KERN_ERR "Error %d adding sysfs file\n", ret);
-		device_remove_file(&dock_device->dev, &dev_attr_docked);
-		device_remove_file(&dock_device->dev, &dev_attr_undock);
-		platform_device_unregister(dock_device);
-		kfree(dock_station);
-		dock_station = NULL;
-		return ret;
-	}
+	if (ret)
+		goto err_unregister2;
+
 	ret = device_create_file(&dock_device->dev, &dev_attr_flags);
-	if (ret) {
-		printk(KERN_ERR "Error %d adding sysfs file\n", ret);
-		device_remove_file(&dock_device->dev, &dev_attr_docked);
-		device_remove_file(&dock_device->dev, &dev_attr_undock);
-		device_remove_file(&dock_device->dev, &dev_attr_uid);
-		platform_device_unregister(dock_device);
-		kfree(dock_station);
-		dock_station = NULL;
-		return ret;
-	}
+	if (ret)
+		goto err_unregister3;
+
 	ret = device_create_file(&dock_device->dev, &dev_attr_type);
 	if (ret)
-		printk(KERN_ERR"Error %d adding sysfs file\n", ret);
+		goto err_unregister4;
 
 	/* Find dependent devices */
 	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
@@ -1036,10 +1012,8 @@ static int dock_add(acpi_handle handle)
 	/* add the dock station as a device dependent on itself */
 	dd = alloc_dock_dependent_device(handle);
 	if (!dd) {
-		kfree(dock_station);
-		dock_station = NULL;
 		ret = -ENOMEM;
-		goto dock_add_err_unregister;
+		goto err_unregister5;
 	}
 	add_dock_dependent_device(dock_station, dd);
 
@@ -1047,13 +1021,20 @@ static int dock_add(acpi_handle handle)
 	list_add(&dock_station->sibling, &dock_stations);
 	return 0;
 
-dock_add_err_unregister:
+err_unregister5:
 	device_remove_file(&dock_device->dev, &dev_attr_type);
-	device_remove_file(&dock_device->dev, &dev_attr_docked);
-	device_remove_file(&dock_device->dev, &dev_attr_undock);
-	device_remove_file(&dock_device->dev, &dev_attr_uid);
+err_unregister4:
 	device_remove_file(&dock_device->dev, &dev_attr_flags);
+err_unregister3:
+	device_remove_file(&dock_device->dev, &dev_attr_uid);
+err_unregister2:
+	device_remove_file(&dock_device->dev, &dev_attr_undock);
+err_unregister1:
+	device_remove_file(&dock_device->dev, &dev_attr_docked);
+err_unregister:
+	printk(KERN_ERR "%s encountered error %d\n", __func__, ret);
 	platform_device_unregister(dock_device);
+out:
 	kfree(dock_station);
 	dock_station = NULL;
 	return ret;

Re: [PATCH v2 1/6] ACPI: dock: clean up error handling paths in dock_add()

[Dmitry Torokhov]

Hi Alex,

On Wed, Oct 14, 2009 at 04:46:16PM -0600, Alex Chiang wrote:
> Remove some copy/paste code in our error handling paths, which makes
> the function smaller and slightly easier to read.

Changing individual attributes into attribute_group would greatly
simplify the code.

> 
> Signed-off-by: Alex Chiang <achiang@hp.com>
> ---
> 
>  drivers/acpi/dock.c |   75 +++++++++++++++++++--------------------------------
>  1 files changed, 28 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
> index 7338b6a..642c7dd 100644
> --- a/drivers/acpi/dock.c
> +++ b/drivers/acpi/dock.c
> @@ -968,11 +968,9 @@ static int dock_add(acpi_handle handle)
>  		platform_device_register_simple(dock_device_name,
>  			dock_station_count, NULL, 0);
>  	dock_device = dock_station->dock_device;
> -	if (IS_ERR(dock_device)) {
> -		kfree(dock_station);
> -		dock_station = NULL;
> -		return PTR_ERR(dock_device);
> -	}
> +	ret = IS_ERR(dock_device) ? PTR_ERR(dock_device) : 0;
> +	if (ret)
> +		goto out;

I think

	if (IS_ERR(dock_device)) {
		ret = PTR_ERR(dock_device);
		goto out;
	}

is more commonly used form.

Thanks.

-- 
Dmitry

Re: [PATCH v2 1/6] ACPI: dock: clean up error handling paths in dock_add()

[Alex Chiang]

* Dmitry Torokhov <dmitry.torokhov@gmail.com>:
> Hi Alex,
> 
> On Wed, Oct 14, 2009 at 04:46:16PM -0600, Alex Chiang wrote:
> > Remove some copy/paste code in our error handling paths, which makes
> > the function smaller and slightly easier to read.
> 
> Changing individual attributes into attribute_group would greatly
> simplify the code.

Good advice, I'll do this, thanks.

> > @@ -968,11 +968,9 @@ static int dock_add(acpi_handle handle)
> >  		platform_device_register_simple(dock_device_name,
> >  			dock_station_count, NULL, 0);
> >  	dock_device = dock_station->dock_device;
> > -	if (IS_ERR(dock_device)) {
> > -		kfree(dock_station);
> > -		dock_station = NULL;
> > -		return PTR_ERR(dock_device);
> > -	}
> > +	ret = IS_ERR(dock_device) ? PTR_ERR(dock_device) : 0;
> > +	if (ret)
> > +		goto out;
> 
> I think
> 
> 	if (IS_ERR(dock_device)) {
> 		ret = PTR_ERR(dock_device);
> 		goto out;
> 	}
> 
> is more commonly used form.

Ok, I'll change to the more idiomatic form.

Thanks for the review.

/ac

[PATCH v2 2/6] ACPI: dock: combine add|alloc_dock_dependent_device

[Alex Chiang]

There's no real need to have a separate allocation step when adding
a dock dependent device.

Combining the two functions is both logical and helps with legibility.

Signed-off-by: Alex Chiang <achiang@hp.com>
---

 drivers/acpi/dock.c |   55 ++++++++++++++++++---------------------------------
 1 files changed, 19 insertions(+), 36 deletions(-)

diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index 642c7dd..10cf833 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -93,40 +93,30 @@ struct dock_dependent_device {
  *                         Dock Dependent device functions                   *
  *****************************************************************************/
 /**
- *  alloc_dock_dependent_device - allocate and init a dependent device
- *  @handle: the acpi_handle of the dependent device
+ * add_dock_dependent_device - associate a device with the dock station
+ * @handle: handle of the dependent device
+ * @ds: The dock station
  *
- *  Allocate memory for a dependent device structure for a device referenced
- *  by the acpi handle
+ * Add the dependent device to the dock's dependent device list.
  */
-static struct dock_dependent_device *
-alloc_dock_dependent_device(acpi_handle handle)
+static int
+add_dock_dependent_device(acpi_handle handle, struct dock_station *ds)
 {
 	struct dock_dependent_device *dd;
 
 	dd = kzalloc(sizeof(*dd), GFP_KERNEL);
-	if (dd) {
-		dd->handle = handle;
-		INIT_LIST_HEAD(&dd->list);
-		INIT_LIST_HEAD(&dd->hotplug_list);
-	}
-	return dd;
-}
+	if (!dd)
+		return -ENOMEM;
+
+	dd->handle = handle;
+	INIT_LIST_HEAD(&dd->list);
+	INIT_LIST_HEAD(&dd->hotplug_list);
 
-/**
- * add_dock_dependent_device - associate a device with the dock station
- * @ds: The dock station
- * @dd: The dependent device
- *
- * Add the dependent device to the dock's dependent device list.
- */
-static void
-add_dock_dependent_device(struct dock_station *ds,
-			  struct dock_dependent_device *dd)
-{
 	spin_lock(&ds->dd_lock);
 	list_add_tail(&dd->list, &ds->dependent_devices);
 	spin_unlock(&ds->dd_lock);
+
+	return 0;
 }
 
 /**
@@ -826,7 +816,6 @@ find_dock_devices(acpi_handle handle, u32 lvl, void *context, void **rv)
 	acpi_status status;
 	acpi_handle tmp, parent;
 	struct dock_station *ds = context;
-	struct dock_dependent_device *dd;
 
 	status = acpi_bus_get_ejd(handle, &tmp);
 	if (ACPI_FAILURE(status)) {
@@ -840,11 +829,9 @@ find_dock_devices(acpi_handle handle, u32 lvl, void *context, void **rv)
 			goto fdd_out;
 	}
 
-	if (tmp == ds->handle) {
-		dd = alloc_dock_dependent_device(handle);
-		if (dd)
-			add_dock_dependent_device(ds, dd);
-	}
+	if (tmp == ds->handle)
+		add_dock_dependent_device(ds, handle);
+
 fdd_out:
 	return AE_OK;
 }
@@ -946,7 +933,6 @@ static DEVICE_ATTR(type, S_IRUGO, show_dock_type, NULL);
 static int dock_add(acpi_handle handle)
 {
 	int ret;
-	struct dock_dependent_device *dd;
 	struct dock_station *dock_station;
 	struct platform_device *dock_device;
 
@@ -1010,12 +996,9 @@ static int dock_add(acpi_handle handle)
 			    NULL);
 
 	/* add the dock station as a device dependent on itself */
-	dd = alloc_dock_dependent_device(handle);
-	if (!dd) {
-		ret = -ENOMEM;
+	ret = add_dock_dependent_device(dock_station, handle);
+	if (ret)
 		goto err_unregister5;
-	}
-	add_dock_dependent_device(dock_station, dd);
 
 	dock_station_count++;
 	list_add(&dock_station->sibling, &dock_stations);

[PATCH v2 3/6] ACPI: dock: remove global 'dock_device_name'

[Alex Chiang]

We only use it in one spot, so it probably gets optimized out, but there's
still no need to use a global variable for this.

Signed-off-by: Alex Chiang <achiang@hp.com>
---

 drivers/acpi/dock.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index 10cf833..e57be55 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -50,7 +50,6 @@ MODULE_PARM_DESC(immediate_undock, "1 (default) will cause the driver to "
 	" before undocking");
 
 static struct atomic_notifier_head dock_notifier_list;
-static char dock_device_name[] = "dock";
 
 static const struct acpi_device_id dock_device_ids[] = {
 	{"LNXDOCK", 0},
@@ -951,7 +950,7 @@ static int dock_add(acpi_handle handle)
 
 	/* initialize platform device stuff */
 	dock_station->dock_device =
-		platform_device_register_simple(dock_device_name,
+		platform_device_register_simple("dock",
 			dock_station_count, NULL, 0);
 	dock_device = dock_station->dock_device;
 	ret = IS_ERR(dock_device) ? PTR_ERR(dock_device) : 0;

[PATCH v2 4/6] ACPI: dock: dock_add - hoist up platform_device_register_simple()

[Alex Chiang]

Move the call to platform_device_register_simple so that we do it
before allocating and initializing our struct dock_station.

Signed-off-by: Alex Chiang <achiang@hp.com>
---

 drivers/acpi/dock.c |   16 ++++++++--------
 1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index e57be55..363be0a 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -935,11 +935,19 @@ static int dock_add(acpi_handle handle)
 	struct dock_station *dock_station;
 	struct platform_device *dock_device;
 
+	dock_device =
+		platform_device_register_simple("dock",
+			dock_station_count, NULL, 0);
+	ret = IS_ERR(dock_device) ? PTR_ERR(dock_device) : 0;
+	if (ret)
+		return ret;
+
 	/* allocate & initialize the dock_station private data */
 	dock_station = kzalloc(sizeof(*dock_station), GFP_KERNEL);
 	if (!dock_station)
 		return -ENOMEM;
 	dock_station->handle = handle;
+	dock_station->dock_device = dock_device;
 	dock_station->last_dock_time = jiffies - HZ;
 	INIT_LIST_HEAD(&dock_station->dependent_devices);
 	INIT_LIST_HEAD(&dock_station->hotplug_devices);
@@ -948,14 +956,6 @@ static int dock_add(acpi_handle handle)
 	mutex_init(&dock_station->hp_lock);
 	ATOMIC_INIT_NOTIFIER_HEAD(&dock_notifier_list);
 
-	/* initialize platform device stuff */
-	dock_station->dock_device =
-		platform_device_register_simple("dock",
-			dock_station_count, NULL, 0);
-	dock_device = dock_station->dock_device;
-	ret = IS_ERR(dock_device) ? PTR_ERR(dock_device) : 0;
-	if (ret)
-		goto out;
 	platform_device_add_data(dock_device, &dock_station,
 		sizeof(struct dock_station *));
 

[PATCH v2 5/6] ACPI: dock: add struct dock_station * directly to platform device data

[Alex Chiang]

Instead of adding a (struct dock_station **) to our dock device's
platform data, we can add the (struct dock_station *) directly.

This change saves us some ugly casting and improves readability.

The cost of making this change is an extra 290 bytes of stack usage,
but this is an infrequently called code-path and unlikely to cause
the kernel to blow up.

Signed-off-by: Alex Chiang <achiang@hp.com>
---

 drivers/acpi/dock.c |   40 +++++++++++++---------------------------
 1 files changed, 13 insertions(+), 27 deletions(-)

diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index 363be0a..25fbf9a 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -843,8 +843,7 @@ static ssize_t show_docked(struct device *dev,
 {
 	struct acpi_device *tmp;
 
-	struct dock_station *dock_station = *((struct dock_station **)
-		dev->platform_data);
+	struct dock_station *dock_station = dev->platform_data;
 
 	if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp)))
 		return snprintf(buf, PAGE_SIZE, "1\n");
@@ -858,8 +857,7 @@ static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
 static ssize_t show_flags(struct device *dev,
 			  struct device_attribute *attr, char *buf)
 {
-	struct dock_station *dock_station = *((struct dock_station **)
-		dev->platform_data);
+	struct dock_station *dock_station = dev->platform_data;
 	return snprintf(buf, PAGE_SIZE, "%d\n", dock_station->flags);
 
 }
@@ -872,8 +870,7 @@ static ssize_t write_undock(struct device *dev, struct device_attribute *attr,
 			   const char *buf, size_t count)
 {
 	int ret;
-	struct dock_station *dock_station = *((struct dock_station **)
-		dev->platform_data);
+	struct dock_station *dock_station = dev->platform_data;
 
 	if (!count)
 		return -EINVAL;
@@ -891,8 +888,7 @@ static ssize_t show_dock_uid(struct device *dev,
 			     struct device_attribute *attr, char *buf)
 {
 	unsigned long long lbuf;
-	struct dock_station *dock_station = *((struct dock_station **)
-		dev->platform_data);
+	struct dock_station *dock_station = dev->platform_data;
 	acpi_status status = acpi_evaluate_integer(dock_station->handle,
 					"_UID", NULL, &lbuf);
 	if (ACPI_FAILURE(status))
@@ -905,8 +901,7 @@ static DEVICE_ATTR(uid, S_IRUGO, show_dock_uid, NULL);
 static ssize_t show_dock_type(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
-	struct dock_station *dock_station = *((struct dock_station **)
-		dev->platform_data);
+	struct dock_station *dock_station = dev->platform_data;
 	char *type;
 
 	if (dock_station->flags & DOCK_IS_DOCK)
@@ -931,21 +926,19 @@ static DEVICE_ATTR(type, S_IRUGO, show_dock_type, NULL);
  */
 static int dock_add(acpi_handle handle)
 {
-	int ret;
-	struct dock_station *dock_station;
+	int ret, id;
+	struct dock_station ds, *dock_station;
 	struct platform_device *dock_device;
 
+	id = dock_station_count;
 	dock_device =
-		platform_device_register_simple("dock",
-			dock_station_count, NULL, 0);
+		platform_device_register_data(NULL, "dock",
+			id, &ds, sizeof(ds));
 	ret = IS_ERR(dock_device) ? PTR_ERR(dock_device) : 0;
 	if (ret)
 		return ret;
 
-	/* allocate & initialize the dock_station private data */
-	dock_station = kzalloc(sizeof(*dock_station), GFP_KERNEL);
-	if (!dock_station)
-		return -ENOMEM;
+	dock_station = dock_device->dev.platform_data;
 	dock_station->handle = handle;
 	dock_station->dock_device = dock_device;
 	dock_station->last_dock_time = jiffies - HZ;
@@ -956,9 +949,6 @@ static int dock_add(acpi_handle handle)
 	mutex_init(&dock_station->hp_lock);
 	ATOMIC_INIT_NOTIFIER_HEAD(&dock_notifier_list);
 
-	platform_device_add_data(dock_device, &dock_station,
-		sizeof(struct dock_station *));
-
 	/* we want the dock device to send uevents */
 	dev_set_uevent_suppress(&dock_device->dev, 0);
 
@@ -1016,9 +1006,6 @@ err_unregister1:
 err_unregister:
 	printk(KERN_ERR "%s encountered error %d\n", __func__, ret);
 	platform_device_unregister(dock_device);
-out:
-	kfree(dock_station);
-	dock_station = NULL;
 	return ret;
 }
 
@@ -1038,6 +1025,8 @@ static int dock_remove(struct dock_station *dock_station)
 				 list)
 	    kfree(dd);
 
+	list_del(&dock_station->sibling);
+
 	/* cleanup sysfs */
 	device_remove_file(&dock_device->dev, &dev_attr_type);
 	device_remove_file(&dock_device->dev, &dev_attr_docked);
@@ -1046,9 +1035,6 @@ static int dock_remove(struct dock_station *dock_station)
 	device_remove_file(&dock_device->dev, &dev_attr_flags);
 	platform_device_unregister(dock_device);
 
-	/* free dock station memory */
-	kfree(dock_station);
-	dock_station = NULL;
 	return 0;
 }
 

[PATCH v2 6/6] ACPI: dock: minor whitespace and style cleanups

[Alex Chiang]

Removed some stray whitespaces
Added whitespace when needed for legibility
Removed unneeded curly braces
Removed useless void casts
Removed unnecessary local variable initialization
Renamed variables to help out with 80-column fixes

Signed-off-by: Alex Chiang <achiang@hp.com>
---

 drivers/acpi/dock.c |  117 +++++++++++++++++++++++----------------------------
 1 files changed, 52 insertions(+), 65 deletions(-)

diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index 25fbf9a..72924ee 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -238,6 +238,7 @@ static int is_battery(acpi_handle handle)
 static int is_ejectable_bay(acpi_handle handle)
 {
 	acpi_handle phandle;
+
 	if (!is_ejectable(handle))
 		return 0;
 	if (is_battery(handle) || is_ata(handle))
@@ -264,14 +265,13 @@ int is_dock_device(acpi_handle handle)
 
 	if (is_dock(handle))
 		return 1;
-	list_for_each_entry(dock_station, &dock_stations, sibling) {
+
+	list_for_each_entry(dock_station, &dock_stations, sibling)
 		if (find_dock_dependent_device(dock_station, handle))
 			return 1;
-	}
 
 	return 0;
 }
-
 EXPORT_SYMBOL_GPL(is_dock_device);
 
 /**
@@ -294,8 +294,6 @@ static int dock_present(struct dock_station *ds)
 	return 0;
 }
 
-
-
 /**
  * dock_create_acpi_device - add new devices to acpi
  * @handle - handle of the device to add
@@ -309,7 +307,7 @@ static int dock_present(struct dock_station *ds)
  */
 static struct acpi_device * dock_create_acpi_device(acpi_handle handle)
 {
-	struct acpi_device *device = NULL;
+	struct acpi_device *device;
 	struct acpi_device *parent_device;
 	acpi_handle parent;
 	int ret;
@@ -326,8 +324,7 @@ static struct acpi_device * dock_create_acpi_device(acpi_handle handle)
 		ret = acpi_bus_add(&device, parent_device, handle,
 			ACPI_BUS_TYPE_DEVICE);
 		if (ret) {
-			pr_debug("error adding bus, %x\n",
-				-ret);
+			pr_debug("error adding bus, %x\n", -ret);
 			return NULL;
 		}
 	}
@@ -353,7 +350,6 @@ static void dock_remove_acpi_device(acpi_handle handle)
 	}
 }
 
-
 /**
  * hotplug_dock_devices - insert or remove devices on the dock station
  * @ds: the dock station
@@ -373,10 +369,9 @@ static void hotplug_dock_devices(struct dock_station *ds, u32 event)
 	/*
 	 * First call driver specific hotplug functions
 	 */
-	list_for_each_entry(dd, &ds->hotplug_devices, hotplug_list) {
+	list_for_each_entry(dd, &ds->hotplug_devices, hotplug_list)
 		if (dd->ops && dd->ops->handler)
 			dd->ops->handler(dd->handle, event, dd->context);
-	}
 
 	/*
 	 * Now make sure that an acpi_device is created for each
@@ -415,6 +410,7 @@ static void dock_event(struct dock_station *ds, u32 event, int num)
 	list_for_each_entry(dd, &ds->hotplug_devices, hotplug_list)
 		if (dd->ops && dd->ops->uevent)
 			dd->ops->uevent(dd->handle, event, dd->context);
+
 	if (num != DOCK_EVENT)
 		kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
 }
@@ -445,8 +441,8 @@ static void eject_dock(struct dock_station *ds)
 	arg.type = ACPI_TYPE_INTEGER;
 	arg.integer.value = 1;
 
-	if (ACPI_FAILURE(acpi_evaluate_object(ds->handle, "_EJ0",
-					      &arg_list, NULL)))
+	status = acpi_evaluate_object(ds->handle, "_EJ0", &arg_list, NULL);
+	if (ACPI_FAILURE(status))
 		pr_debug("Failed to evaluate _EJ0!\n");
 }
 
@@ -566,7 +562,6 @@ int register_dock_notifier(struct notifier_block *nb)
 
 	return atomic_notifier_chain_register(&dock_notifier_list, nb);
 }
-
 EXPORT_SYMBOL_GPL(register_dock_notifier);
 
 /**
@@ -580,7 +575,6 @@ void unregister_dock_notifier(struct notifier_block *nb)
 
 	atomic_notifier_chain_unregister(&dock_notifier_list, nb);
 }
-
 EXPORT_SYMBOL_GPL(unregister_dock_notifier);
 
 /**
@@ -625,7 +619,6 @@ register_hotplug_dock_device(acpi_handle handle, struct acpi_dock_ops *ops,
 
 	return ret;
 }
-
 EXPORT_SYMBOL_GPL(register_hotplug_dock_device);
 
 /**
@@ -646,7 +639,6 @@ void unregister_hotplug_dock_device(acpi_handle handle)
 			dock_del_hotplug_device(dock_station, dd);
 	}
 }
-
 EXPORT_SYMBOL_GPL(unregister_hotplug_dock_device);
 
 /**
@@ -761,7 +753,7 @@ struct dock_data {
 
 static void acpi_dock_deferred_cb(void *context)
 {
-	struct dock_data *data = (struct dock_data *)context;
+	struct dock_data *data = context;
 
 	dock_notify(data->handle, data->event, data->ds);
 	kfree(data);
@@ -771,23 +763,22 @@ static int acpi_dock_notifier_call(struct notifier_block *this,
 	unsigned long event, void *data)
 {
 	struct dock_station *dock_station;
-	acpi_handle handle = (acpi_handle)data;
+	acpi_handle handle = data;
 
 	if (event != ACPI_NOTIFY_BUS_CHECK && event != ACPI_NOTIFY_DEVICE_CHECK
 	   && event != ACPI_NOTIFY_EJECT_REQUEST)
 		return 0;
 	list_for_each_entry(dock_station, &dock_stations, sibling) {
 		if (dock_station->handle == handle) {
-			struct dock_data *dock_data;
+			struct dock_data *dd;
 
-			dock_data = kmalloc(sizeof(*dock_data), GFP_KERNEL);
-			if (!dock_data)
+			dd = kmalloc(sizeof(*dd), GFP_KERNEL);
+			if (!dd)
 				return 0;
-			dock_data->handle = handle;
-			dock_data->event = event;
-			dock_data->ds = dock_station;
-			acpi_os_hotplug_execute(acpi_dock_deferred_cb,
-				dock_data);
+			dd->handle = handle;
+			dd->event = event;
+			dd->ds = dock_station;
+			acpi_os_hotplug_execute(acpi_dock_deferred_cb, dd);
 			return 0 ;
 		}
 	}
@@ -928,29 +919,29 @@ static int dock_add(acpi_handle handle)
 {
 	int ret, id;
 	struct dock_station ds, *dock_station;
-	struct platform_device *dock_device;
+	struct platform_device *dd;
 
 	id = dock_station_count;
-	dock_device =
-		platform_device_register_data(NULL, "dock",
-			id, &ds, sizeof(ds));
-	ret = IS_ERR(dock_device) ? PTR_ERR(dock_device) : 0;
+	dd = platform_device_register_data(NULL, "dock", id, &ds, sizeof(ds));
+	ret = IS_ERR(dd) ? PTR_ERR(dd) : 0;
 	if (ret)
 		return ret;
 
-	dock_station = dock_device->dev.platform_data;
+	dock_station = dd->dev.platform_data;
+
 	dock_station->handle = handle;
-	dock_station->dock_device = dock_device;
+	dock_station->dock_device = dd;
 	dock_station->last_dock_time = jiffies - HZ;
-	INIT_LIST_HEAD(&dock_station->dependent_devices);
-	INIT_LIST_HEAD(&dock_station->hotplug_devices);
-	INIT_LIST_HEAD(&dock_station->sibling);
-	spin_lock_init(&dock_station->dd_lock);
+
 	mutex_init(&dock_station->hp_lock);
+	spin_lock_init(&dock_station->dd_lock);
+	INIT_LIST_HEAD(&dock_station->sibling);
+	INIT_LIST_HEAD(&dock_station->hotplug_devices);
 	ATOMIC_INIT_NOTIFIER_HEAD(&dock_notifier_list);
+	INIT_LIST_HEAD(&dock_station->dependent_devices);
 
 	/* we want the dock device to send uevents */
-	dev_set_uevent_suppress(&dock_device->dev, 0);
+	dev_set_uevent_suppress(&dd->dev, 0);
 
 	if (is_dock(handle))
 		dock_station->flags |= DOCK_IS_DOCK;
@@ -959,30 +950,29 @@ static int dock_add(acpi_handle handle)
 	if (is_battery(handle))
 		dock_station->flags |= DOCK_IS_BAT;
 
-	ret = device_create_file(&dock_device->dev, &dev_attr_docked);
+	ret = device_create_file(&dd->dev, &dev_attr_docked);
 	if (ret)
 		goto err_unregister;
 
-	ret = device_create_file(&dock_device->dev, &dev_attr_undock);
+	ret = device_create_file(&dd->dev, &dev_attr_undock);
 	if (ret)
 		goto err_unregister1;
 
-	ret = device_create_file(&dock_device->dev, &dev_attr_uid);
+	ret = device_create_file(&dd->dev, &dev_attr_uid);
 	if (ret)
 		goto err_unregister2;
 
-	ret = device_create_file(&dock_device->dev, &dev_attr_flags);
+	ret = device_create_file(&dd->dev, &dev_attr_flags);
 	if (ret)
 		goto err_unregister3;
 
-	ret = device_create_file(&dock_device->dev, &dev_attr_type);
+	ret = device_create_file(&dd->dev, &dev_attr_type);
 	if (ret)
 		goto err_unregister4;
 
 	/* Find dependent devices */
-	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
-			    ACPI_UINT32_MAX, find_dock_devices, dock_station,
-			    NULL);
+	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX,
+			    find_dock_devices, dock_station, NULL);
 
 	/* add the dock station as a device dependent on itself */
 	ret = add_dock_dependent_device(dock_station, handle);
@@ -994,38 +984,37 @@ static int dock_add(acpi_handle handle)
 	return 0;
 
 err_unregister5:
-	device_remove_file(&dock_device->dev, &dev_attr_type);
+	device_remove_file(&dd->dev, &dev_attr_type);
 err_unregister4:
-	device_remove_file(&dock_device->dev, &dev_attr_flags);
+	device_remove_file(&dd->dev, &dev_attr_flags);
 err_unregister3:
-	device_remove_file(&dock_device->dev, &dev_attr_uid);
+	device_remove_file(&dd->dev, &dev_attr_uid);
 err_unregister2:
-	device_remove_file(&dock_device->dev, &dev_attr_undock);
+	device_remove_file(&dd->dev, &dev_attr_undock);
 err_unregister1:
-	device_remove_file(&dock_device->dev, &dev_attr_docked);
+	device_remove_file(&dd->dev, &dev_attr_docked);
 err_unregister:
 	printk(KERN_ERR "%s encountered error %d\n", __func__, ret);
-	platform_device_unregister(dock_device);
+	platform_device_unregister(dd);
 	return ret;
 }
 
 /**
  * dock_remove - free up resources related to the dock station
  */
-static int dock_remove(struct dock_station *dock_station)
+static int dock_remove(struct dock_station *ds)
 {
 	struct dock_dependent_device *dd, *tmp;
-	struct platform_device *dock_device = dock_station->dock_device;
+	struct platform_device *dock_device = ds->dock_device;
 
 	if (!dock_station_count)
 		return 0;
 
 	/* remove dependent devices */
-	list_for_each_entry_safe(dd, tmp, &dock_station->dependent_devices,
-				 list)
-	    kfree(dd);
+	list_for_each_entry_safe(dd, tmp, &ds->dependent_devices, list)
+		kfree(dd);
 
-	list_del(&dock_station->sibling);
+	list_del(&ds->sibling);
 
 	/* cleanup sysfs */
 	device_remove_file(&dock_device->dev, &dev_attr_type);
@@ -1052,11 +1041,10 @@ find_dock(acpi_handle handle, u32 lvl, void *context, void **rv)
 {
 	acpi_status status = AE_OK;
 
-	if (is_dock(handle)) {
-		if (dock_add(handle) >= 0) {
+	if (is_dock(handle))
+		if (dock_add(handle) >= 0)
 			status = AE_CTRL_TERMINATE;
-		}
-	}
+
 	return status;
 }
 
@@ -1094,8 +1082,7 @@ static int __init dock_init(void)
 
 static void __exit dock_exit(void)
 {
-	struct dock_station *dock_station;
-	struct dock_station *tmp;
+	struct dock_station *tmp, *dock_station;
 
 	unregister_acpi_bus_notifier(&dock_acpi_notifier);
 	list_for_each_entry_safe(dock_station, tmp, &dock_stations, sibling)