| Message ID | 20190517231337.27859-2-eduval@amazon.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/2] hwmon: core: add thermal sensors only if dev->of_node is present | expand |
Hi Eduardo, On Fri, May 17, 2019 at 04:13:36PM -0700, Eduardo Valentin wrote: > 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. > Makes sense. I'd apply it as-is, but it would be better if you resend it to the list to give others a chance to comment. Thanks, Guenter > 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> > --- > 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 fcdbac4a56e3..6b3559f58b67 100644 > --- a/drivers/hwmon/hwmon.c > +++ b/drivers/hwmon/hwmon.c > @@ -619,7 +619,7 @@ __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; > -- > 2.21.0 >
On Tue, May 28, 2019 at 08:08:21AM -0700, Guenter Roeck wrote: > Hi Eduardo, > > On Fri, May 17, 2019 at 04:13:36PM -0700, Eduardo Valentin wrote: > > 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. > > > Makes sense. I'd apply it as-is, but it would be better if you resend > it to the list to give others a chance to comment. Ok Cool. Yeah, the patches were copied to the mailing list. Only the cover letter somehow I forgot to copy the mailing lists while git-sending-email. I will resend the two patches (and the cover letter) after fixing the comment on patch 2/2. > > Thanks, > Guenter > > > 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> > > --- > > 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 fcdbac4a56e3..6b3559f58b67 100644 > > --- a/drivers/hwmon/hwmon.c > > +++ b/drivers/hwmon/hwmon.c > > @@ -619,7 +619,7 @@ __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; > > -- > > 2.21.0 > >
diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c index fcdbac4a56e3..6b3559f58b67 100644 --- a/drivers/hwmon/hwmon.c +++ b/drivers/hwmon/hwmon.c @@ -619,7 +619,7 @@ __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;
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. 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> --- drivers/hwmon/hwmon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)