[ Upstream commit c41dd48e21fae3e55b3670ccf2eb562fc1f6a67d ]
Drivers may register to hwmon and request for also registering with the thermal subsystem (HWMON_C_REGISTER_TZ). However, some of these driver, e.g. marvell phy, may be probed from Device Tree or being dynamically allocated, and in the later case, it will not have a dev->of_node entry.
Registering with hwmon without the dev->of_node may result in different outcomes depending on the device tree, which may be a bit misleading. If the device tree blob has no 'thermal-zones' node, the *hwmon_device_register*() family functions are going to gracefully succeed, because of-thermal, *thermal_zone_of_sensor_register() return -ENODEV in this case, and the hwmon error path handles this error code as success to cover for the case where CONFIG_THERMAL_OF is not set. However, if the device tree blob has the 'thermal-zones' entry, the *hwmon_device_register*() will always fail on callers with no dev->of_node, propagating -EINVAL.
If dev->of_node is not present, calling of-thermal does not make sense. For this reason, this patch checks first if the device has a of_node before going over the process of registering with the thermal subsystem of-thermal interface. And in this case, when a caller of *hwmon_device_register*() with HWMON_C_REGISTER_TZ and no dev->of_node will still register with hwmon, but not with the thermal subsystem. If all the hwmon part bits are in place, the registration will succeed.
Fixes: d560168b5d0f ("hwmon: (core) New hwmon registration API") Cc: Jean Delvare jdelvare@suse.com Cc: Guenter Roeck linux@roeck-us.net Cc: linux-hwmon@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Eduardo Valentin eduval@amazon.com Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwmon/hwmon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c index c22dc1e07911..c38883f748a1 100644 --- a/drivers/hwmon/hwmon.c +++ b/drivers/hwmon/hwmon.c @@ -633,7 +633,7 @@ __hwmon_device_register(struct device *dev, const char *name, void *drvdata, if (err) goto free_hwmon;
- if (dev && chip && chip->ops->read && + if (dev && dev->of_node && chip && chip->ops->read && chip->info[0]->type == hwmon_chip && (chip->info[0]->config[0] & HWMON_C_REGISTER_TZ)) { const struct hwmon_channel_info **info = chip->info;