diff options
| author | Maud Spierings <maudspierings@gocontroll.com> | 2025-03-07 11:10:43 +0300 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2025-03-07 17:57:52 +0300 |
| commit | 7953605976f55acd4f297d310e6b0b2944f4bdc8 (patch) | |
| tree | d48dc887850ea8699ca6e79c621056deb798e1d8 | |
| parent | ee65d9e63046de1de2a5383ba6f998634c86c42c (diff) | |
| download | linux-7953605976f55acd4f297d310e6b0b2944f4bdc8.tar.xz | |
hwmon: (ntc_thermistor) return error instead of clipping on OOB
When the ntc is reading Out Of Bounds instead of clipping to the nearest
limit (min/max) return -ENODATA. This prevents malfunctioning sensors
from sending a device into a shutdown loop due to a critical trip.
This implementation will only work for ntc type thermistors if a ptc
type is to be implemented the min/max ohm calculation must be adjusted
to take that into account.
Signed-off-by: Maud Spierings <maudspierings@gocontroll.com>
Link: https://lore.kernel.org/r/20250307-ntc_oob-v2-1-bba2d32b1a8e@gocontroll.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
| -rw-r--r-- | drivers/hwmon/ntc_thermistor.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/drivers/hwmon/ntc_thermistor.c b/drivers/hwmon/ntc_thermistor.c index b5352900463f..7c759669b26f 100644 --- a/drivers/hwmon/ntc_thermistor.c +++ b/drivers/hwmon/ntc_thermistor.c @@ -387,12 +387,9 @@ static int get_ohm_of_thermistor(struct ntc_data *data, unsigned int uv) puo = data->pullup_ohm; pdo = data->pulldown_ohm; - if (uv == 0) - return (data->connect == NTC_CONNECTED_POSITIVE) ? - INT_MAX : 0; - if (uv >= puv) - return (data->connect == NTC_CONNECTED_POSITIVE) ? - 0 : INT_MAX; + /* faulty adc value */ + if (uv == 0 || uv >= puv) + return -ENODATA; if (data->connect == NTC_CONNECTED_POSITIVE && puo == 0) n = div_u64(pdo * (puv - uv), uv); @@ -404,8 +401,10 @@ static int get_ohm_of_thermistor(struct ntc_data *data, unsigned int uv) else n = div64_u64_safe(pdo * puo * uv, pdo * (puv - uv) - puo * uv); - if (n > INT_MAX) - n = INT_MAX; + /* sensor out of bounds */ + if (n > data->comp[0].ohm || n < data->comp[data->n_comp - 1].ohm) + return -ENODATA; + return n; } |