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iio: dac: ad5446: Fix ad5622_write() return value

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commit 558df982d4ead9cac628153d0d7b60feae05ddc8 upstream.

On success i2c_master_send() returns the number of bytes written. The
call from iio_write_channel_info(), however, expects the return value to
be zero on success.

This bug causes incorrect consumption of the sysfs buffer in
iio_write_channel_info(). When writing more than two characters to
out_voltage0_raw, the ad5446 write handler is called multiple times
causing unexpected behavior.

Fixes: 3ec36a2cf0d5 ("iio:ad5446: Add support for I2C based DACs")
Signed-off-by: Pekka Korpinen <pekka.korpinen@iki.fi>
Link: https://lore.kernel.org/r/20210929185755.2384-1-pekka.korpinen@iki.fi
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Pekka Korpinen 2021-09-29 21:57:55 +03:00 committed by Greg Kroah-Hartman
parent f01e16d324
commit 8ce0bc6962
1 changed files with 8 additions and 1 deletions
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9
drivers/iio/dac/ad5446.c
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@ -527,8 +527,15 @@ static int ad5622_write(struct ad5446_state *st, unsigned val)
{
struct i2c_client *client = to_i2c_client(st->dev);
__be16 data = cpu_to_be16(val);
int ret;
return i2c_master_send(client, (char *)&data, sizeof(data));
ret = i2c_master_send(client, (char *)&data, sizeof(data));
if (ret < 0)
return ret;
if (ret != sizeof(data))
return -EIO;
return 0;
}
/**