hwmon: (pmbus/isl68137) Fix unchecked return value and use sysfs_emit()

isl68137_avs_enable_show_page() uses the return value of
pmbus_read_byte_data() without checking for errors. If the I2C transaction
fails, a negative error code is passed through bitwise operations,
producing incorrect output.

Add an error check to propagate the return value if it is negative.
Additionally, modernize the callback by replacing sprintf()
with sysfs_emit().

Fixes: 038a9c3d1e424 ("hwmon: (pmbus/isl68137) Add driver for Intersil ISL68137 PWM Controller")
Cc: stable@vger.kernel.org
Signed-off-by: Sanman Pradhan <psanman@juniper.net>
Link: https://lore.kernel.org/r/20260318193952.47908-2-sanman.pradhan@hpe.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/pmbus/isl68137.c b/drivers/hwmon/pmbus/isl68137.c
index 97b61836f53a45fd6b03772c7703c40f26ca9b37..e7dac26b5be615213a5844b425e95941f829133d 100644 (file)
--- a/drivers/hwmon/pmbus/isl68137.c
+++ b/drivers/hwmon/pmbus/isl68137.c
@@ -98,8 +98,11 @@ static ssize_t isl68137_avs_enable_show_page(struct i2c_client *client,
 {
        int val = pmbus_read_byte_data(client, page, PMBUS_OPERATION);
 
-       return sprintf(buf, "%d\n",
-                      (val & ISL68137_VOUT_AVS) == ISL68137_VOUT_AVS ? 1 : 0);
+       if (val < 0)
+               return val;
+
+       return sysfs_emit(buf, "%d\n",
+                          (val & ISL68137_VOUT_AVS) == ISL68137_VOUT_AVS);
 }
 
 static ssize_t isl68137_avs_enable_store_page(struct i2c_client *client,