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i8k: Convert to use to hwmon_device_register_with_groups hwmon API
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Simplify code and fix race condition caused by registering
hwmon device prior to creating sysfs attributes.

Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Guenter Roeck authored and Greg Kroah-Hartman committed Dec 19, 2013
1 parent 12186f5 commit 82ba1d3
Showing 1 changed file with 54 additions and 78 deletions.
132 changes: 54 additions & 78 deletions drivers/char/i8k.c
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Original file line number Diff line number Diff line change
Expand Up @@ -66,6 +66,11 @@
static DEFINE_MUTEX(i8k_mutex);
static char bios_version[4];
static struct device *i8k_hwmon_dev;
static u32 i8k_hwmon_flags;

#define I8K_HWMON_HAVE_TEMP1 (1 << 0)
#define I8K_HWMON_HAVE_FAN1 (1 << 1)
#define I8K_HWMON_HAVE_FAN2 (1 << 2)

MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
Expand Down Expand Up @@ -502,8 +507,7 @@ static ssize_t i8k_hwmon_show_label(struct device *dev,
struct device_attribute *devattr,
char *buf)
{
static const char *labels[4] = {
"i8k",
static const char *labels[3] = {
"CPU",
"Left Fan",
"Right Fan",
Expand All @@ -518,100 +522,72 @@ static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
I8K_FAN_LEFT);
static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
I8K_FAN_RIGHT);
static SENSOR_DEVICE_ATTR(name, S_IRUGO, i8k_hwmon_show_label, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 1);
static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 2);
static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_label, NULL, 3);
static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 0);
static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 1);
static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_label, NULL, 2);

static struct attribute *i8k_attrs[] = {
&dev_attr_temp1_input.attr, /* 0 */
&sensor_dev_attr_temp1_label.dev_attr.attr, /* 1 */
&sensor_dev_attr_fan1_input.dev_attr.attr, /* 2 */
&sensor_dev_attr_fan1_label.dev_attr.attr, /* 3 */
&sensor_dev_attr_fan2_input.dev_attr.attr, /* 4 */
&sensor_dev_attr_fan2_label.dev_attr.attr, /* 5 */
NULL
};

static void i8k_hwmon_remove_files(struct device *dev)
static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
int index)
{
device_remove_file(dev, &dev_attr_temp1_input);
device_remove_file(dev, &sensor_dev_attr_fan1_input.dev_attr);
device_remove_file(dev, &sensor_dev_attr_fan2_input.dev_attr);
device_remove_file(dev, &sensor_dev_attr_temp1_label.dev_attr);
device_remove_file(dev, &sensor_dev_attr_fan1_label.dev_attr);
device_remove_file(dev, &sensor_dev_attr_fan2_label.dev_attr);
device_remove_file(dev, &sensor_dev_attr_name.dev_attr);
if ((index == 0 || index == 1) &&
!(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
return 0;
if ((index == 2 || index == 3) &&
!(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN1))
return 0;
if ((index == 4 || index == 5) &&
!(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
return 0;

return attr->mode;
}

static const struct attribute_group i8k_group = {
.attrs = i8k_attrs,
.is_visible = i8k_is_visible,
};
__ATTRIBUTE_GROUPS(i8k);

static int __init i8k_init_hwmon(void)
{
int err;

i8k_hwmon_dev = hwmon_device_register(NULL);
if (IS_ERR(i8k_hwmon_dev)) {
err = PTR_ERR(i8k_hwmon_dev);
i8k_hwmon_dev = NULL;
pr_err("hwmon registration failed (%d)\n", err);
return err;
}

/* Required name attribute */
err = device_create_file(i8k_hwmon_dev,
&sensor_dev_attr_name.dev_attr);
if (err)
goto exit_unregister;
i8k_hwmon_flags = 0;

/* CPU temperature attributes, if temperature reading is OK */
err = i8k_get_temp(0);
if (err < 0) {
dev_dbg(i8k_hwmon_dev,
"Not creating temperature attributes (%d)\n", err);
} else {
err = device_create_file(i8k_hwmon_dev, &dev_attr_temp1_input);
if (err)
goto exit_remove_files;
err = device_create_file(i8k_hwmon_dev,
&sensor_dev_attr_temp1_label.dev_attr);
if (err)
goto exit_remove_files;
}
if (err >= 0)
i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;

/* Left fan attributes, if left fan is present */
err = i8k_get_fan_status(I8K_FAN_LEFT);
if (err < 0) {
dev_dbg(i8k_hwmon_dev,
"Not creating %s fan attributes (%d)\n", "left", err);
} else {
err = device_create_file(i8k_hwmon_dev,
&sensor_dev_attr_fan1_input.dev_attr);
if (err)
goto exit_remove_files;
err = device_create_file(i8k_hwmon_dev,
&sensor_dev_attr_fan1_label.dev_attr);
if (err)
goto exit_remove_files;
}
if (err >= 0)
i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;

/* Right fan attributes, if right fan is present */
err = i8k_get_fan_status(I8K_FAN_RIGHT);
if (err < 0) {
dev_dbg(i8k_hwmon_dev,
"Not creating %s fan attributes (%d)\n", "right", err);
} else {
err = device_create_file(i8k_hwmon_dev,
&sensor_dev_attr_fan2_input.dev_attr);
if (err)
goto exit_remove_files;
err = device_create_file(i8k_hwmon_dev,
&sensor_dev_attr_fan2_label.dev_attr);
if (err)
goto exit_remove_files;
}
if (err >= 0)
i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;

i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "i8k", NULL,
i8k_groups);
if (IS_ERR(i8k_hwmon_dev)) {
err = PTR_ERR(i8k_hwmon_dev);
i8k_hwmon_dev = NULL;
pr_err("hwmon registration failed (%d)\n", err);
return err;
}
return 0;

exit_remove_files:
i8k_hwmon_remove_files(i8k_hwmon_dev);
exit_unregister:
hwmon_device_unregister(i8k_hwmon_dev);
return err;
}

static void __exit i8k_exit_hwmon(void)
{
i8k_hwmon_remove_files(i8k_hwmon_dev);
hwmon_device_unregister(i8k_hwmon_dev);
}

static struct dmi_system_id i8k_dmi_table[] __initdata = {
Expand Down Expand Up @@ -774,7 +750,7 @@ static int __init i8k_init(void)

static void __exit i8k_exit(void)
{
i8k_exit_hwmon();
hwmon_device_unregister(i8k_hwmon_dev);
remove_proc_entry("i8k", NULL);
}

Expand Down

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