From d0a228d903425e653f18a4341e60c0538afb6d41 Mon Sep 17 00:00:00 2001 From: Salah Triki Date: Mon, 27 Apr 2026 22:33:19 +0100 Subject: [PATCH] iio: dac: max5821: fix return value check in powerdown sync The function max5821_sync_powerdown_mode() returned the result of i2c_master_send() directly. If a partial transfer occurred, it would be incorrectly treated as a success by the caller. While the caller currently handles the positive return value of 2 as success, this patch refactors the function to return 0 on full success and -EIO on short writes. This ensures robust error handling for incomplete transfers and improves code maintainability by using sizeof(outbuf). Fixes: 472988972737 ("iio: add support of the max5821") Signed-off-by: Salah Triki Reviewed-by: Andy Shevchenko Cc: Signed-off-by: Jonathan Cameron --- drivers/iio/dac/max5821.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/iio/dac/max5821.c b/drivers/iio/dac/max5821.c index e7e29359f8fe..dd4e35460195 100644 --- a/drivers/iio/dac/max5821.c +++ b/drivers/iio/dac/max5821.c @@ -90,6 +90,7 @@ static int max5821_sync_powerdown_mode(struct max5821_data *data, const struct iio_chan_spec *chan) { u8 outbuf[2]; + int ret; outbuf[0] = MAX5821_EXTENDED_COMMAND_MODE; @@ -103,7 +104,13 @@ static int max5821_sync_powerdown_mode(struct max5821_data *data, else outbuf[1] |= MAX5821_EXTENDED_POWER_UP; - return i2c_master_send(data->client, outbuf, 2); + ret = i2c_master_send(data->client, outbuf, sizeof(outbuf)); + if (ret < 0) + return ret; + if (ret != sizeof(outbuf)) + return -EIO; + + return 0; } static ssize_t max5821_write_dac_powerdown(struct iio_dev *indio_dev,