When user tried to read some fields like hysteresis from IIO sysfs on some systems, it fails. The reason is that this field is a byte field and caller of sensor_hub_get_feature() passes a buffer of 4 bytes. Here the function sensor_hub_get_feature() copies the single byte from the report to the caller buffer and returns "1" as the number of bytes copied. So caller can use the return value. But this is done by multiple callers, so if we just change the sensor_hub_get_feature so that caller buffer is initialized with 0s then we don't to change all functions. Signed-off-by: Song Hongyan <hongyan.song@xxxxxxxxx> --- changes: update comments drivers/hid/hid-sensor-hub.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/hid/hid-sensor-hub.c b/drivers/hid/hid-sensor-hub.c index 658a607..b74d954 100644 --- a/drivers/hid/hid-sensor-hub.c +++ b/drivers/hid/hid-sensor-hub.c @@ -252,6 +252,7 @@ int sensor_hub_get_feature(struct hid_sensor_hub_device *hsdev, u32 report_id, int report_size; int ret = 0; + memset(buffer, 0, buffer_size); mutex_lock(&data->mutex); report = sensor_hub_report(report_id, hsdev->hdev, HID_FEATURE_REPORT); if (!report || (field_index >= report->maxfield) || -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html