[PATCH v2] hwmon: (pt5161l) Fix invalid temperature reading

From: Cosmo Chou
Date: Mon Aug 19 2024 - 06:48:47 EST


The temperature reading function was using a signed long for the ADC
code, which could lead to mishandling of invalid codes on 32-bit
platforms. This allowed out-of-range ADC codes to be incorrectly
interpreted as valid values and used in temperature calculations.

Change adc_code to u32 to ensure that invalid ADC codes are correctly
identified on all platforms.

Fixes: 1b2ca93cd059 ("hwmon: Add driver for Astera Labs PT5161L retimer")
Signed-off-by: Cosmo Chou <chou.cosmo@xxxxxxxxx>
---
Change log:

v2:
- Fix build warnings of dev_dbg().

---
drivers/hwmon/pt5161l.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hwmon/pt5161l.c b/drivers/hwmon/pt5161l.c
index b0d58a26d499..a9f0b23f9e76 100644
--- a/drivers/hwmon/pt5161l.c
+++ b/drivers/hwmon/pt5161l.c
@@ -427,7 +427,7 @@ static int pt5161l_read(struct device *dev, enum hwmon_sensor_types type,
struct pt5161l_data *data = dev_get_drvdata(dev);
int ret;
u8 buf[8];
- long adc_code;
+ u32 adc_code;

switch (attr) {
case hwmon_temp_input:
@@ -449,7 +449,7 @@ static int pt5161l_read(struct device *dev, enum hwmon_sensor_types type,

adc_code = buf[3] << 24 | buf[2] << 16 | buf[1] << 8 | buf[0];
if (adc_code == 0 || adc_code >= 0x3ff) {
- dev_dbg(dev, "Invalid adc_code %lx\n", adc_code);
+ dev_dbg(dev, "Invalid adc_code %x\n", adc_code);
return -EIO;
}

--
2.34.1