From: Eduardo Valentin <eduval@amazon.com>
To: Guenter Roeck <linux@roeck-us.net>
Cc: Eduardo Valentin <eduval@amazon.com>,
Jean Delvare <jdelvare@suse.com>, <linux-hwmon@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: [PATCH 1/2] hwmon: core: add thermal sensors only if dev->of_node is present
Date: Fri, 17 May 2019 16:13:36 -0700 [thread overview]
Message-ID: <20190517231337.27859-2-eduval@amazon.com> (raw)
In-Reply-To: <20190517231337.27859-1-eduval@amazon.com>
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(-)
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
next parent reply other threads:[~2019-05-17 23:13 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190517231337.27859-1-eduval@amazon.com>
2019-05-17 23:13 ` Eduardo Valentin [this message]
2019-05-28 15:08 ` [PATCH 1/2] hwmon: core: add thermal sensors only if dev->of_node is present Guenter Roeck
2019-05-29 23:12 ` Eduardo Valentin
2019-05-17 23:13 ` [PATCH 2/2] hwmon: core: fix potential memory leak in *hwmon_device_register* Eduardo Valentin
2019-05-28 15:06 ` Guenter Roeck
2019-05-29 23:14 ` Eduardo Valentin
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