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author | Pekka Korpinen <pekka.korpinen@iki.fi> | 2021-09-29 21:57:55 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-18 21:16:07 +0300 |
commit | a92d075cb4b5be5f6be75e9f128e8fb32fc5257a (patch) | |
tree | 2fb8cfae12587d0354d8a43313b0f717418bb376 /drivers/iio | |
parent | bd297200b747908f4725880e34f0298e313b4634 (diff) | |
download | linux-a92d075cb4b5be5f6be75e9f128e8fb32fc5257a.tar.xz |
iio: dac: ad5446: Fix ad5622_write() return value
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>
Diffstat (limited to 'drivers/iio')
-rw-r--r-- | drivers/iio/dac/ad5446.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/iio/dac/ad5446.c b/drivers/iio/dac/ad5446.c index 488ec69967d6..e50718422411 100644 --- a/drivers/iio/dac/ad5446.c +++ b/drivers/iio/dac/ad5446.c @@ -531,8 +531,15 @@ 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; + + ret = i2c_master_send(client, (char *)&data, sizeof(data)); + if (ret < 0) + return ret; + if (ret != sizeof(data)) + return -EIO; - return i2c_master_send(client, (char *)&data, sizeof(data)); + return 0; } /* |