Re: [PATCH 02/11] Input: iqs7222 - report malformed properties

Dmitry Torokhov
2022-09-08T21:21:22Z

On Thu, Sep 08, 2022 at 08:15:39AM -0500, Jeff LaBundy wrote:
> Nonzero return values of several calls to fwnode_property_read_u32()
> are silenty ignored, leaving no way to know that the properties were
> not applied in the event of an error.
>
> To solve this problem, follow the design pattern used throughout the
> rest of the driver by first checking if the property is present, and
> then evaluating the return value of fwnode_property_read_u32().
>
> Fixes: e505edaedcb9 ("Input: add support for Azoteq IQS7222A/B/C")
> Signed-off-by: Jeff LaBundy <jeff@labundy.com>
> ---
> drivers/input/misc/iqs7222.c | 65 ++++++++++++++++++++++++++++++------
> 1 file changed, 55 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/input/misc/iqs7222.c b/drivers/input/misc/iqs7222.c
> index 04c1050d845c..fdade24caa8a 100644
> --- a/drivers/input/misc/iqs7222.c
> +++ b/drivers/input/misc/iqs7222.c
> @@ -1819,8 +1819,17 @@ static int iqs7222_parse_chan(struct iqs7222_private *iqs7222, int chan_index)
> chan_setup[0] |= IQS7222_CHAN_SETUP_0_REF_MODE_FOLLOW;
> chan_setup[4] = val * 42 + 1048;
>
> - if (!fwnode_property_read_u32(chan_node, "azoteq,ref-weight",
> - &val)) {
> + if (fwnode_property_present(chan_node, "azoteq,ref-weight")) {
> + error = fwnode_property_read_u32(chan_node,
> + "azoteq,ref-weight",
> + &val);

fwnode_property_read_u32() returns EINVAL if property is missing, so
maybe have:

error = fwnode_property_read_u32(chan_node,
"azoteq,ref-weight", &val);
if (!error) {
...
} else {
if (error != -EINVAL) {
dev_err(&client->dev,
"Failed to read %s reference weight: %d\n",
fwnode_get_name(chan_node), error);
goto put_chan_node;
}
}

to avoid double calls into property handling code?

--
Dmitry