Re: [PATCH v3 2/4] iio: trigger: move to the cleanup.h magic

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Mon, 18 Mar 2024 15:12:20 +0200
Andy Shevchenko <andy.shevchenko@gmail.com> wrote:

> On Mon, Mar 18, 2024 at 2:33 PM Jonathan Cameron
> <Jonathan.Cameron@huawei.com> wrote:
> > On Sat, 16 Mar 2024 21:32:56 +0200
> > Andy Shevchenko <andy.shevchenko@gmail.com> wrote:  
> > > Thu, Feb 29, 2024 at 04:10:26PM +0100, Nuno Sa kirjoitti:  
> 
> ...
> 
> > > > -   ret = bitmap_find_free_region(trig->pool,
> > > > -                                 CONFIG_IIO_CONSUMERS_PER_TRIGGER,
> > > > -                                 ilog2(1));  
> > >  
> > > > +           ret = bitmap_find_free_region(trig->pool,
> > > > +                                         CONFIG_IIO_CONSUMERS_PER_TRIGGER,
> > > > +                                         ilog2(1));  
> > >
> > > Despite being in the original code, this is funny magic constant...  
> >
> > Not that magic, build time config variable to avoid adding complexity
> > of dynamic expansion of various structures. We could have picked a big
> > number but someone will always want a bigger one and from what I recall
> > actually make it expandable was nasty to do.  Been a long time, though
> > so I'm open to patches that get rid of this in favor of a dynamic solution.  
> 
> I didn't get you, sorry. Logarithm (by any base) from 1 is 0. Writing
> it as arithmetic expression seems funny to me.

Ah. I was looking at the line above ;)

That one is because it lines up with the docs for bitmap_find_free_region()
Last parameter is order, but seems more natural to express it in number of bits
hence the 1 rather that superficially looking like we are asking for
a region of length 0.


>