On Fri, 01 Mar 2024 18:14:50 +0100
Nuno Sa via B4 Relay <devnull+nuno.sa.analog.com@xxxxxxxxxx> wrote:
> From: Nuno Sa <nuno.sa@xxxxxxxxxx>
>
> Use dev_err_probe() in the probe() path. While at it, made some simple
> improvements:
> * Declare a struct device *dev helper. This also makes the style more
> consistent (some places the helper was used and not in other places);
> * Explicitly included the err.h and errno.h headers;
> * Removed an useless else if();
> * Removed some unnecessary line breaks.
>
> Signed-off-by: Nuno Sa <nuno.sa@xxxxxxxxxx>
I'd rather see a proposal for dev_errp_probe() than a local solution.
We can fallback to local solution if it doesn't meet with approval!
Not that many uses in IIO so far, but seems some potential elsewhere.
There are already a few return ERR_PTR(dev_err_probe()) cases in tree
for low hanging fruit + looks like scmi_iio could benefit as another case
in IIO.
> ---
> drivers/iio/temperature/ltc2983.c | 262 ++++++++++++++++++--------------------
> 1 file changed, 122 insertions(+), 140 deletions(-)
>
> diff --git a/drivers/iio/temperature/ltc2983.c b/drivers/iio/temperature/ltc2983.c
> index 3c4524d57b8e..592887097117 100644
> --- a/drivers/iio/temperature/ltc2983.c
> +++ b/drivers/iio/temperature/ltc2983.c
> @@ -8,6 +8,8 @@
> #include <linux/bitfield.h>
> #include <linux/completion.h>
> #include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/errno.h>
> #include <linux/kernel.h>
> #include <linux/iio/iio.h>
> #include <linux/interrupt.h>
> @@ -206,6 +208,13 @@ enum {
> #define to_temp(_sensor) \
> container_of(_sensor, struct ltc2983_temp, sensor)
>
> +/* Helper macro for returning error pointers in probe() paths. */
> +#define ltc2983_errp_probe(dev, ret, fmt, ...) ({ \
> + int ___ret = dev_err_probe(dev, ret, fmt, ##__VA_ARGS__); \
> + \
> + ERR_PTR(___ret); \
Given it's all wrapped up in a macro, I'd avoid the need for the ___ to try
and prevent shadowing an existing variable by just going with
ERR_PTR(dev_err_probe(dev, ret, fmt, ##__VA_ARGS__))
and no ({ complexities.
If you really need to use a local variable, just through the hoops to make it unique
like the cleanup.h macros do.
> +})
> +
