On Fri, Jun 10, 2022 at 10:48 AM Nuno Sá <nuno.sa@xxxxxxxxxx> wrote:
>
> APIs like of_iio_channel_get_by_name() and of_iio_channel_get_all() were
> returning a mix of NULL and error pointers being NULL the way to
> "notify" that we should do a "system" lookup for channels. This make
> it very confusing and prone to errors as commit dbbccf7c20bf
> ("iio: inkern: fix return value in devm_of_iio_channel_get_by_name()")
> proves. On top of this, patterns like 'if (channel != NULL) return channel'
> were being used where channel could actually be an error code which
> makes the code hard to read.
...
> np = np->parent;
> if (np && !of_get_property(np, "io-channel-ranges", NULL))
> - return NULL;
> + return chan;
Shouldn't it return a dedicated error code and not some arbitrary one?
It may be I missed something and chan has a correct error code in this
case...
...
> + if (nummaps == 0) /* return -ENODEV to search map table */
Comment is superfluous, the next line is self-explaining.
> + return ERR_PTR(-ENODEV);
...
> - if (channel != NULL)
> + if (!IS_ERR(channel) || PTR_ERR(channel) == -EPROBE_DEFER)
Btw, in the GPIO library we have a macro or inliner (don't remember)
that represents such a conditional.
Perhaps make it (if it's a macro) global, or introduce an inline in IIO?
Okay, it's here:
https://elixir.bootlin.com/linux/v5.19-rc1/source/drivers/gpio/gpiolib.h#L179
It's similar, but not the same, so just play with an idea to introduce
something in this file, maybe it's worth doing this, maybe not.
--
With Best Regards,
Andy Shevchenko
