Re: [PATCH 1/2] iio: pressure: bmp280: Allow multiple chips id per family of devices

From: Andy Shevchenko
Date: Fri Aug 18 2023 - 07:20:21 EST


On Thu, Aug 17, 2023 at 11:05:21PM +0200, Angel Iglesias wrote:
> Improve device detection in certain chip families known to have various
> chip ids.

...

> + ret = -EINVAL;

Why do you need this...

> + for (i = 0; i < data->chip_info->num_chip_id; i++) {
> + if (chip_id == data->chip_info->chip_id[i]) {

> + ret = 0;

..and this...

> + break;
> + }
> + }

> + if (ret) {

...and this?

You can simply do

for (i = 0; i < data->chip_info->num_chip_id; i++) {
if (chip_id == data->chip_info->chip_id[i])
break;
}
if (i < data->chip_info->num_chip_id) {

...

> + // 0x<id>, so four chars per number plus one space + ENDL
> + size_t nbuf = 5*data->chip_info->num_chip_id*sizeof(char);

Besides lack of spaces...

> + char *buf = kmalloc(nbuf, GFP_KERNEL);

...this at least should be kmalloc_array() and on top maybe something from
overflow.h will be needed.

> + if (!buf)
> + return ret;
> +
> + for (i = 0; i < data->chip_info->num_chip_id; i++)
> + snprintf(&buf[i*5], nbuf, "0x%x ", data->chip_info->chip_id[i]);
> + buf[nbuf-1] = '\0';
> +
> + dev_err(dev, "bad chip id: expected [ %s ] got 0x%x\n", buf, chip_id);
> + kfree(buf);
> + return ret;
> }

...

> - const unsigned int chip_id;

Yeah, this const makes a little sense...

> + const unsigned int *chip_id;

...but not this :-)

What I'm wondering is why it's int and not u8 / u16
(as it seems only a byte value there).

> + int num_chip_id;

unsigned.

--
With Best Regards,
Andy Shevchenko