| Message ID | 20210202142113.5456-1-matwey@sai.msu.ru (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] hwmon: lm75: Handle broken device nodes gracefully | expand |
On 2/2/21 6:21 AM, Matwey V. Kornilov wrote: > There is a logical flaw in lm75_probe() function introduced in > > commit e97a45f1b460 ("hwmon: (lm75) Add OF device ID table") > > Note, that of_device_get_match_data() returns NULL when no match > found. This is the case when OF node exists but has unknown is found. > compatible line, while the module is still loaded via i2c > detection. > > arch/powerpc/boot/dts/fsl/p2041rdb.dts: > > lm75b@48 { > compatible = "nxp,lm75a"; > reg = <0x48>; > }; > > In this case, the sensor is mistakenly considered as ADT75 variant. > > Fixes: e97a45f1b460 ("hwmon: (lm75) Add OF device ID table") > Signed-off-by: Matwey V. Kornilov <matwey@sai.msu.ru> > --- > drivers/hwmon/lm75.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c > index e447febd121a..130ad5042107 100644 > --- a/drivers/hwmon/lm75.c > +++ b/drivers/hwmon/lm75.c > @@ -561,9 +561,15 @@ static int lm75_probe(struct i2c_client *client) > int status, err; > enum lm75_type kind; > > - if (client->dev.of_node) > - kind = (enum lm75_type)of_device_get_match_data(&client->dev); > - else > + if (dev->of_node) { > + const struct of_device_id *match = > + of_match_device(dev->driver->of_match_table, dev); > + > + if (!match) > + return -ENODEV; > + > + kind = (enum lm75_type)(match->data); > + } else > kind = i2c_match_id(lm75_ids, client)->driver_data; > else needs to be in { } to match if. Guenter > if (!i2c_check_functionality(client->adapter, >
diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c index e447febd121a..130ad5042107 100644 --- a/drivers/hwmon/lm75.c +++ b/drivers/hwmon/lm75.c @@ -561,9 +561,15 @@ static int lm75_probe(struct i2c_client *client) int status, err; enum lm75_type kind; - if (client->dev.of_node) - kind = (enum lm75_type)of_device_get_match_data(&client->dev); - else + if (dev->of_node) { + const struct of_device_id *match = + of_match_device(dev->driver->of_match_table, dev); + + if (!match) + return -ENODEV; + + kind = (enum lm75_type)(match->data); + } else kind = i2c_match_id(lm75_ids, client)->driver_data; if (!i2c_check_functionality(client->adapter,
There is a logical flaw in lm75_probe() function introduced in commit e97a45f1b460 ("hwmon: (lm75) Add OF device ID table") Note, that of_device_get_match_data() returns NULL when no match found. This is the case when OF node exists but has unknown compatible line, while the module is still loaded via i2c detection. arch/powerpc/boot/dts/fsl/p2041rdb.dts: lm75b@48 { compatible = "nxp,lm75a"; reg = <0x48>; }; In this case, the sensor is mistakenly considered as ADT75 variant. Fixes: e97a45f1b460 ("hwmon: (lm75) Add OF device ID table") Signed-off-by: Matwey V. Kornilov <matwey@sai.msu.ru> --- drivers/hwmon/lm75.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)