| Message ID | 20161025232621.GB20339@obsidianresearch.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
On 10/25/2016 04:26 PM, Jason Gunthorpe wrote: > This is the expected thing for a hwmon driver to do, this changes > the sysfs paths from, say: > > /sys/bus/i2c/devices/0-002c/temp1_input > > to: > > /sys/bus/i2c/devices/0-002c/hwmon/hwmon0/temp1_input > > Which is consistent with accepted changes to other hwmon drivers > (eg lm75) > No need to mention that. > Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> > --- > drivers/hwmon/lm87.c | 108 +++++++++++++++++++-------------------------------- > 1 file changed, 39 insertions(+), 69 deletions(-) > > Tested on a PPC platform > > diff --git a/drivers/hwmon/lm87.c b/drivers/hwmon/lm87.c > index 47598989cd3c..70896c078d20 100644 > --- a/drivers/hwmon/lm87.c > +++ b/drivers/hwmon/lm87.c > @@ -154,7 +154,6 @@ static u8 LM87_REG_TEMP_LOW[3] = { 0x3A, 0x38, 0x2C }; > */ > > struct lm87_data { > - struct device *hwmon_dev; > struct mutex update_lock; > char valid; /* zero until following fields are valid */ > unsigned long last_updated; /* In jiffies */ > @@ -181,6 +180,8 @@ struct lm87_data { > u16 alarms; /* register values, combined */ > u8 vid; /* register values, combined */ > u8 vrm; > + > + const struct attribute_group *attr_groups[5]; There can be up to 5 active groups total, so this array needs to have 6 entries (it needs to be NULL_terminated). > }; > > static inline int lm87_read_value(struct i2c_client *client, u8 reg) > @@ -195,7 +196,7 @@ static inline int lm87_write_value(struct i2c_client *client, u8 reg, u8 value) > > static struct lm87_data *lm87_update_device(struct device *dev) > { > - struct i2c_client *client = to_i2c_client(dev); > + struct i2c_client *client = dev_get_drvdata(dev); > struct lm87_data *data = i2c_get_clientdata(client); > > mutex_lock(&data->update_lock); > @@ -309,7 +310,7 @@ static ssize_t show_in_max(struct device *dev, > static ssize_t set_in_min(struct device *dev, struct device_attribute *attr, > const char *buf, size_t count) > { > - struct i2c_client *client = to_i2c_client(dev); > + struct i2c_client *client = dev_get_drvdata(dev); > struct lm87_data *data = i2c_get_clientdata(client); > int nr = to_sensor_dev_attr(attr)->index; > long val; > @@ -330,7 +331,7 @@ static ssize_t set_in_min(struct device *dev, struct device_attribute *attr, > static ssize_t set_in_max(struct device *dev, struct device_attribute *attr, > const char *buf, size_t count) > { > - struct i2c_client *client = to_i2c_client(dev); > + struct i2c_client *client = dev_get_drvdata(dev); > struct lm87_data *data = i2c_get_clientdata(client); > int nr = to_sensor_dev_attr(attr)->index; > long val; > @@ -396,7 +397,7 @@ static ssize_t show_temp_high(struct device *dev, > static ssize_t set_temp_low(struct device *dev, struct device_attribute *attr, > const char *buf, size_t count) > { > - struct i2c_client *client = to_i2c_client(dev); > + struct i2c_client *client = dev_get_drvdata(dev); > struct lm87_data *data = i2c_get_clientdata(client); > int nr = to_sensor_dev_attr(attr)->index; > long val; > @@ -416,7 +417,7 @@ static ssize_t set_temp_low(struct device *dev, struct device_attribute *attr, > static ssize_t set_temp_high(struct device *dev, struct device_attribute *attr, > const char *buf, size_t count) > { > - struct i2c_client *client = to_i2c_client(dev); > + struct i2c_client *client = dev_get_drvdata(dev); > struct lm87_data *data = i2c_get_clientdata(client); > int nr = to_sensor_dev_attr(attr)->index; > long val; > @@ -495,7 +496,7 @@ static ssize_t show_fan_div(struct device *dev, > static ssize_t set_fan_min(struct device *dev, struct device_attribute *attr, > const char *buf, size_t count) > { > - struct i2c_client *client = to_i2c_client(dev); > + struct i2c_client *client = dev_get_drvdata(dev); > struct lm87_data *data = i2c_get_clientdata(client); > int nr = to_sensor_dev_attr(attr)->index; > long val; > @@ -522,7 +523,7 @@ static ssize_t set_fan_min(struct device *dev, struct device_attribute *attr, > static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr, > const char *buf, size_t count) > { > - struct i2c_client *client = to_i2c_client(dev); > + struct i2c_client *client = dev_get_drvdata(dev); > struct lm87_data *data = i2c_get_clientdata(client); > int nr = to_sensor_dev_attr(attr)->index; > long val; > @@ -635,7 +636,7 @@ static ssize_t show_aout(struct device *dev, struct device_attribute *attr, > static ssize_t set_aout(struct device *dev, struct device_attribute *attr, > const char *buf, size_t count) > { > - struct i2c_client *client = to_i2c_client(dev); > + struct i2c_client *client = dev_get_drvdata(dev); > struct lm87_data *data = i2c_get_clientdata(client); > long val; > int err; > @@ -841,20 +842,6 @@ static int lm87_detect(struct i2c_client *client, struct i2c_board_info *info) > return 0; > } > > -static void lm87_remove_files(struct i2c_client *client) > -{ > - struct device *dev = &client->dev; > - > - sysfs_remove_group(&dev->kobj, &lm87_group); > - sysfs_remove_group(&dev->kobj, &lm87_group_in6); > - sysfs_remove_group(&dev->kobj, &lm87_group_fan1); > - sysfs_remove_group(&dev->kobj, &lm87_group_in7); > - sysfs_remove_group(&dev->kobj, &lm87_group_fan2); > - sysfs_remove_group(&dev->kobj, &lm87_group_temp3); > - sysfs_remove_group(&dev->kobj, &lm87_group_in0_5); > - sysfs_remove_group(&dev->kobj, &lm87_group_vid); > -} > - > static void lm87_init_client(struct i2c_client *client) > { > struct lm87_data *data = i2c_get_clientdata(client); > @@ -909,7 +896,9 @@ static void lm87_init_client(struct i2c_client *client) > static int lm87_probe(struct i2c_client *client, const struct i2c_device_id *id) > { > struct lm87_data *data; > + struct device *hwmon_dev; > int err; > + unsigned int group_tail = 0; > > data = devm_kzalloc(&client->dev, sizeof(struct lm87_data), GFP_KERNEL); > if (!data) > @@ -930,58 +919,42 @@ static int lm87_probe(struct i2c_client *client, const struct i2c_device_id *id) > data->in_scale[6] = 1875; > data->in_scale[7] = 1875; > > - /* Register sysfs hooks */ > - err = sysfs_create_group(&client->dev.kobj, &lm87_group); > - if (err) > - goto exit_stop; > - > - if (data->channel & CHAN_NO_FAN(0)) { > - err = sysfs_create_group(&client->dev.kobj, &lm87_group_in6); > - if (err) > - goto exit_remove; > - } else { > - err = sysfs_create_group(&client->dev.kobj, &lm87_group_fan1); > - if (err) > - goto exit_remove; > - } > - > - if (data->channel & CHAN_NO_FAN(1)) { > - err = sysfs_create_group(&client->dev.kobj, &lm87_group_in7); > - if (err) > - goto exit_remove; > - } else { > - err = sysfs_create_group(&client->dev.kobj, &lm87_group_fan2); > - if (err) > - goto exit_remove; > - } > - > - if (data->channel & CHAN_TEMP3) { > - err = sysfs_create_group(&client->dev.kobj, &lm87_group_temp3); > - if (err) > - goto exit_remove; > - } else { > - err = sysfs_create_group(&client->dev.kobj, &lm87_group_in0_5); > - if (err) > - goto exit_remove; > - } > + /* > + * Construct the list of attributes, the list depends on the > + * configuration of the chip > + */ > + data->attr_groups[group_tail++] = &lm87_group; > + if (data->channel & CHAN_NO_FAN(0)) > + data->attr_groups[group_tail++] = &lm87_group_in6; > + else > + data->attr_groups[group_tail++] = &lm87_group_fan1; > + > + if (data->channel & CHAN_NO_FAN(1)) > + data->attr_groups[group_tail++] = &lm87_group_in7; > + else > + data->attr_groups[group_tail++] = &lm87_group_fan2; > + > + if (data->channel & CHAN_TEMP3) > + data->attr_groups[group_tail++] = &lm87_group_temp3; > + else > + data->attr_groups[group_tail++] = &lm87_group_in0_5; > > if (!(data->channel & CHAN_NO_VID)) { > data->vrm = vid_which_vrm(); > - err = sysfs_create_group(&client->dev.kobj, &lm87_group_vid); > - if (err) > - goto exit_remove; > + data->attr_groups[group_tail++] = &lm87_group_vid; > } > > - data->hwmon_dev = hwmon_device_register(&client->dev); > - if (IS_ERR(data->hwmon_dev)) { > - err = PTR_ERR(data->hwmon_dev); > - goto exit_remove; > + WARN_ON(group_tail > ARRAY_SIZE(data->attr_groups)); > + Please, no. We should be able to count. Besides, it is wrong - it would have to be >=. > + hwmon_dev = devm_hwmon_device_register_with_groups( > + &client->dev, client->name, client, data->attr_groups); > + if (IS_ERR(hwmon_dev)) { > + err = PTR_ERR(hwmon_dev); > + goto exit_stop; > } > > return 0; > > -exit_remove: > - lm87_remove_files(client); > exit_stop: > lm87_write_value(client, LM87_REG_CONFIG, data->config); > return err; > @@ -991,9 +964,6 @@ static int lm87_remove(struct i2c_client *client) > { > struct lm87_data *data = i2c_get_clientdata(client); > > - hwmon_device_unregister(data->hwmon_dev); > - lm87_remove_files(client); > - > lm87_write_value(client, LM87_REG_CONFIG, data->config); Strictly speaking this is now racy: The sysfs attributes still exist here, meaning the chip can still be accessed. Consider using devm_add_action(); then you can drop the remove function entirely, and simplify error cleanup in the probe function. > return 0; > } > -- To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Oct 25, 2016 at 06:50:01PM -0700, Guenter Roeck wrote: > >+ > >+ const struct attribute_group *attr_groups[5]; > > There can be up to 5 active groups total, so this array needs to have > 6 entries (it needs to be NULL_terminated). Agh right, I forgot about that. I will send a v2 > > { > > struct lm87_data *data = i2c_get_clientdata(client); > > > >- hwmon_device_unregister(data->hwmon_dev); > >- lm87_remove_files(client); > >- > > lm87_write_value(client, LM87_REG_CONFIG, data->config); > > Strictly speaking this is now racy: The sysfs attributes still exist here, > meaning the chip can still be accessed. Consider using devm_add_action(); > then you can drop the remove function entirely, and simplify error cleanup > in the probe function. I guess, but that is very obscure. If you unload the driver while monitoring it with sysfs and the boot firmware left the chip in the low power state then a sysfs right might race and return garbage.. I can switch it to use hwmon_device_register_with_groups and put the hwmon_device_unregister back - I'm not sure wrapping the write in devm would be a simplification.. Thanks, Jason -- To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 10/25/2016 07:54 PM, Jason Gunthorpe wrote: > On Tue, Oct 25, 2016 at 06:50:01PM -0700, Guenter Roeck wrote: >>> + >>> + const struct attribute_group *attr_groups[5]; >> >> There can be up to 5 active groups total, so this array needs to have >> 6 entries (it needs to be NULL_terminated). > > Agh right, I forgot about that. I will send a v2 > >>> { >>> struct lm87_data *data = i2c_get_clientdata(client); >>> >>> - hwmon_device_unregister(data->hwmon_dev); >>> - lm87_remove_files(client); >>> - >>> lm87_write_value(client, LM87_REG_CONFIG, data->config); >> >> Strictly speaking this is now racy: The sysfs attributes still exist here, >> meaning the chip can still be accessed. Consider using devm_add_action(); >> then you can drop the remove function entirely, and simplify error cleanup >> in the probe function. > > I guess, but that is very obscure. If you unload the driver while > monitoring it with sysfs and the boot firmware left the chip in the > low power state then a sysfs right might race and return garbage.. > Exactly my point. > I can switch it to use hwmon_device_register_with_groups and put the > hwmon_device_unregister back - I'm not sure wrapping the write in devm > would be a simplification.. > Sure, that is a possibility. I personally prefer devm_add_action(). Effectively you claim that devm_add_action() would not add value, meaning there are - as of today - 67 calls in the kernel which don't add value. I'll leave that up to you, though - not worth arguing about. Thanks, Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/hwmon/lm87.c b/drivers/hwmon/lm87.c index 47598989cd3c..70896c078d20 100644 --- a/drivers/hwmon/lm87.c +++ b/drivers/hwmon/lm87.c @@ -154,7 +154,6 @@ static u8 LM87_REG_TEMP_LOW[3] = { 0x3A, 0x38, 0x2C }; */ struct lm87_data { - struct device *hwmon_dev; struct mutex update_lock; char valid; /* zero until following fields are valid */ unsigned long last_updated; /* In jiffies */ @@ -181,6 +180,8 @@ struct lm87_data { u16 alarms; /* register values, combined */ u8 vid; /* register values, combined */ u8 vrm; + + const struct attribute_group *attr_groups[5]; }; static inline int lm87_read_value(struct i2c_client *client, u8 reg) @@ -195,7 +196,7 @@ static inline int lm87_write_value(struct i2c_client *client, u8 reg, u8 value) static struct lm87_data *lm87_update_device(struct device *dev) { - struct i2c_client *client = to_i2c_client(dev); + struct i2c_client *client = dev_get_drvdata(dev); struct lm87_data *data = i2c_get_clientdata(client); mutex_lock(&data->update_lock); @@ -309,7 +310,7 @@ static ssize_t show_in_max(struct device *dev, static ssize_t set_in_min(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - struct i2c_client *client = to_i2c_client(dev); + struct i2c_client *client = dev_get_drvdata(dev); struct lm87_data *data = i2c_get_clientdata(client); int nr = to_sensor_dev_attr(attr)->index; long val; @@ -330,7 +331,7 @@ static ssize_t set_in_min(struct device *dev, struct device_attribute *attr, static ssize_t set_in_max(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - struct i2c_client *client = to_i2c_client(dev); + struct i2c_client *client = dev_get_drvdata(dev); struct lm87_data *data = i2c_get_clientdata(client); int nr = to_sensor_dev_attr(attr)->index; long val; @@ -396,7 +397,7 @@ static ssize_t show_temp_high(struct device *dev, static ssize_t set_temp_low(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - struct i2c_client *client = to_i2c_client(dev); + struct i2c_client *client = dev_get_drvdata(dev); struct lm87_data *data = i2c_get_clientdata(client); int nr = to_sensor_dev_attr(attr)->index; long val; @@ -416,7 +417,7 @@ static ssize_t set_temp_low(struct device *dev, struct device_attribute *attr, static ssize_t set_temp_high(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - struct i2c_client *client = to_i2c_client(dev); + struct i2c_client *client = dev_get_drvdata(dev); struct lm87_data *data = i2c_get_clientdata(client); int nr = to_sensor_dev_attr(attr)->index; long val; @@ -495,7 +496,7 @@ static ssize_t show_fan_div(struct device *dev, static ssize_t set_fan_min(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - struct i2c_client *client = to_i2c_client(dev); + struct i2c_client *client = dev_get_drvdata(dev); struct lm87_data *data = i2c_get_clientdata(client); int nr = to_sensor_dev_attr(attr)->index; long val; @@ -522,7 +523,7 @@ static ssize_t set_fan_min(struct device *dev, struct device_attribute *attr, static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - struct i2c_client *client = to_i2c_client(dev); + struct i2c_client *client = dev_get_drvdata(dev); struct lm87_data *data = i2c_get_clientdata(client); int nr = to_sensor_dev_attr(attr)->index; long val; @@ -635,7 +636,7 @@ static ssize_t show_aout(struct device *dev, struct device_attribute *attr, static ssize_t set_aout(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - struct i2c_client *client = to_i2c_client(dev); + struct i2c_client *client = dev_get_drvdata(dev); struct lm87_data *data = i2c_get_clientdata(client); long val; int err; @@ -841,20 +842,6 @@ static int lm87_detect(struct i2c_client *client, struct i2c_board_info *info) return 0; } -static void lm87_remove_files(struct i2c_client *client) -{ - struct device *dev = &client->dev; - - sysfs_remove_group(&dev->kobj, &lm87_group); - sysfs_remove_group(&dev->kobj, &lm87_group_in6); - sysfs_remove_group(&dev->kobj, &lm87_group_fan1); - sysfs_remove_group(&dev->kobj, &lm87_group_in7); - sysfs_remove_group(&dev->kobj, &lm87_group_fan2); - sysfs_remove_group(&dev->kobj, &lm87_group_temp3); - sysfs_remove_group(&dev->kobj, &lm87_group_in0_5); - sysfs_remove_group(&dev->kobj, &lm87_group_vid); -} - static void lm87_init_client(struct i2c_client *client) { struct lm87_data *data = i2c_get_clientdata(client); @@ -909,7 +896,9 @@ static void lm87_init_client(struct i2c_client *client) static int lm87_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct lm87_data *data; + struct device *hwmon_dev; int err; + unsigned int group_tail = 0; data = devm_kzalloc(&client->dev, sizeof(struct lm87_data), GFP_KERNEL); if (!data) @@ -930,58 +919,42 @@ static int lm87_probe(struct i2c_client *client, const struct i2c_device_id *id) data->in_scale[6] = 1875; data->in_scale[7] = 1875; - /* Register sysfs hooks */ - err = sysfs_create_group(&client->dev.kobj, &lm87_group); - if (err) - goto exit_stop; - - if (data->channel & CHAN_NO_FAN(0)) { - err = sysfs_create_group(&client->dev.kobj, &lm87_group_in6); - if (err) - goto exit_remove; - } else { - err = sysfs_create_group(&client->dev.kobj, &lm87_group_fan1); - if (err) - goto exit_remove; - } - - if (data->channel & CHAN_NO_FAN(1)) { - err = sysfs_create_group(&client->dev.kobj, &lm87_group_in7); - if (err) - goto exit_remove; - } else { - err = sysfs_create_group(&client->dev.kobj, &lm87_group_fan2); - if (err) - goto exit_remove; - } - - if (data->channel & CHAN_TEMP3) { - err = sysfs_create_group(&client->dev.kobj, &lm87_group_temp3); - if (err) - goto exit_remove; - } else { - err = sysfs_create_group(&client->dev.kobj, &lm87_group_in0_5); - if (err) - goto exit_remove; - } + /* + * Construct the list of attributes, the list depends on the + * configuration of the chip + */ + data->attr_groups[group_tail++] = &lm87_group; + if (data->channel & CHAN_NO_FAN(0)) + data->attr_groups[group_tail++] = &lm87_group_in6; + else + data->attr_groups[group_tail++] = &lm87_group_fan1; + + if (data->channel & CHAN_NO_FAN(1)) + data->attr_groups[group_tail++] = &lm87_group_in7; + else + data->attr_groups[group_tail++] = &lm87_group_fan2; + + if (data->channel & CHAN_TEMP3) + data->attr_groups[group_tail++] = &lm87_group_temp3; + else + data->attr_groups[group_tail++] = &lm87_group_in0_5; if (!(data->channel & CHAN_NO_VID)) { data->vrm = vid_which_vrm(); - err = sysfs_create_group(&client->dev.kobj, &lm87_group_vid); - if (err) - goto exit_remove; + data->attr_groups[group_tail++] = &lm87_group_vid; } - data->hwmon_dev = hwmon_device_register(&client->dev); - if (IS_ERR(data->hwmon_dev)) { - err = PTR_ERR(data->hwmon_dev); - goto exit_remove; + WARN_ON(group_tail > ARRAY_SIZE(data->attr_groups)); + + hwmon_dev = devm_hwmon_device_register_with_groups( + &client->dev, client->name, client, data->attr_groups); + if (IS_ERR(hwmon_dev)) { + err = PTR_ERR(hwmon_dev); + goto exit_stop; } return 0; -exit_remove: - lm87_remove_files(client); exit_stop: lm87_write_value(client, LM87_REG_CONFIG, data->config); return err; @@ -991,9 +964,6 @@ static int lm87_remove(struct i2c_client *client) { struct lm87_data *data = i2c_get_clientdata(client); - hwmon_device_unregister(data->hwmon_dev); - lm87_remove_files(client); - lm87_write_value(client, LM87_REG_CONFIG, data->config); return 0; }
This is the expected thing for a hwmon driver to do, this changes the sysfs paths from, say: /sys/bus/i2c/devices/0-002c/temp1_input to: /sys/bus/i2c/devices/0-002c/hwmon/hwmon0/temp1_input Which is consistent with accepted changes to other hwmon drivers (eg lm75) Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> --- drivers/hwmon/lm87.c | 108 +++++++++++++++++++-------------------------------- 1 file changed, 39 insertions(+), 69 deletions(-) Tested on a PPC platform