Re: [PATCH] iio: adc: ad9467: Fix the "don't allow reading vref if not available" case

[David Lechner]

On 12/5/24 2:47 PM, Christophe JAILLET wrote:
> The commit in Fixes add a special case when only one possible scale is
> available.
> If several scales are available, it sets the .read_avail field of the
> struct iio_info to ad9467_read_avail().
> 
> However, this field already holds this function pointer, so the code is a
> no-op.
> 
> Update ad9467_info to actually reflect the intent described in the commit
> message. Keep .read_avail to NULL, unless it is changed to
> ad9467_read_avail() in the probe at runtime.
> 
> Fixes: b92f94f74826 ("iio: adc: ad9467: don't allow reading vref if not available")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> This patch is compile tested only and is completely speculative.
> 
> Another solution would be to keep ad9467_info as a const struct as it was
> before and add a new ad9467_info_no_read structure.

Yes, making it static const again would be best. Modifying static structs
that are shared between all instances like this based on the properties of
a single instance is asking for trouble down the road.

> This way, instead of writing in the structure itself, we would choose at
> runtime which version to use. The main benefit would be keep this structure
> with function pointer const.
> ---