iio: imu: st_lsm6dsx: Fix selection of ST_LSM6DS3_ID

At the moment, attempting to probe a device with ST_LSM6DS3_ID
(e.g. using the st,lsm6ds3 compatible) fails with:

    st_lsm6dsx_i2c 1-006b: unsupported whoami [69]

... even though 0x69 is the whoami listed for ST_LSM6DS3_ID.

This happens because st_lsm6dsx_check_whoami() also attempts
to match unspecified (zero-initialized) entries in the "id" array.
ST_LSM6DS3_ID = 0 will therefore match any entry in
st_lsm6dsx_sensor_settings (here: the first), because none of them
actually have all 12 entries listed in the "id" array.

Avoid this by additionally checking if "name" is set,
which is only set for valid entries in the "id" array.

Note: Although the problem was introduced earlier it did not surface until
commit a49c052cd9fa ("iio: imu: st_lsm6dsx: add support for accel/gyro unit of lsm9ds1")
because ST_LSM6DS3_ID was the first entry in st_lsm6dsx_sensor_settings.

Fixes: fc73bde68d16 ("iio: imu: st_lsm6dsx: add support to multiple devices with the same settings")
Cc: <stable@vger.kernel.org> # 5.4
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
index a7d40c02ce6b53a7a2606b454acb283738f7f33a..b921dd9e108faa5bfd017a1a7550c5095ff0c924 100644 (file)
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
@@ -1301,7 +1301,8 @@ static int st_lsm6dsx_check_whoami(struct st_lsm6dsx_hw *hw, int id,
 
        for (i = 0; i < ARRAY_SIZE(st_lsm6dsx_sensor_settings); i++) {
                for (j = 0; j < ST_LSM6DSX_MAX_ID; j++) {
-                       if (id == st_lsm6dsx_sensor_settings[i].id[j].hw_id)
+                       if (st_lsm6dsx_sensor_settings[i].id[j].name &&
+                           id == st_lsm6dsx_sensor_settings[i].id[j].hw_id)
                                break;
                }
                if (j < ST_LSM6DSX_MAX_ID)