From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> commit 57572cacd36e6d4be7722d7770d23f4430219827 upstream. The regulator enables were after the check on the chip variant, which was very unlikely to return a correct value when not powered. Presumably all the device anyone is testing on have a regulator that is already powered up when this code runs for reasons beyond the scope of this driver. Move the read call down a few lines. Fixes: 3cf7ded15e40 ("iio: accel: bma400: basic regulator support") Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Reviewed-by: Dan Robertson <dan@xxxxxxxxxxxxxxx> Cc: <Stable@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20221002144133.3771029-1-jic23@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/iio/accel/bma400_core.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) --- a/drivers/iio/accel/bma400_core.c +++ b/drivers/iio/accel/bma400_core.c @@ -737,18 +737,6 @@ static int bma400_init(struct bma400_dat unsigned int val; int ret; - /* Try to read chip_id register. It must return 0x90. */ - ret = regmap_read(data->regmap, BMA400_CHIP_ID_REG, &val); - if (ret) { - dev_err(data->dev, "Failed to read chip id register\n"); - return ret; - } - - if (val != BMA400_ID_REG_VAL) { - dev_err(data->dev, "Chip ID mismatch\n"); - return -ENODEV; - } - data->regulators[BMA400_VDD_REGULATOR].supply = "vdd"; data->regulators[BMA400_VDDIO_REGULATOR].supply = "vddio"; ret = devm_regulator_bulk_get(data->dev, @@ -774,6 +762,18 @@ static int bma400_init(struct bma400_dat if (ret) return ret; + /* Try to read chip_id register. It must return 0x90. */ + ret = regmap_read(data->regmap, BMA400_CHIP_ID_REG, &val); + if (ret) { + dev_err(data->dev, "Failed to read chip id register\n"); + return ret; + } + + if (val != BMA400_ID_REG_VAL) { + dev_err(data->dev, "Chip ID mismatch\n"); + return -ENODEV; + } + ret = bma400_get_power_mode(data); if (ret) { dev_err(data->dev, "Failed to get the initial power-mode\n");