Re: context_loss_count error value

[Tomi Valkeinen <tomi.valkeinen@ti.com>]

On Wed, 2011-05-25 at 13:30 -0700, Kevin Hilman wrote:
> Tomi Valkeinen <tomi.valkeinen@ti.com> writes:
> 
> > On Wed, 2011-05-25 at 11:34 -0700, Kevin Hilman wrote:
> >> Tomi Valkeinen <tomi.valkeinen@ti.com> writes:

<snip>

> >> 
> >> > +		if (off_mode_enabled) {
> >> > +			count = (count + 1) & 0x7fffffff;
> >> > +			dummy_context_loss_counter = count;
> >> > +		}
> >> 
> >> Again, I don't think this masking is needed.   count is already an
> >> 'int', so when it gets bigger than INT_MAX, it will wrap.
> >
> > When count is INT_MAX and one is added to it, it'll wrap to INT_MIN,
> > i.e. maximum negative value, which would be an error value. So by
> > masking out the highest bit we'll get nonnegative count range from 0 to
> > INT_MAX.
> >
> > Perhaps a comment would be justified here =).
> 
> Indeed, and using INT_MAX instead of the hard-coded constants would help
> readability also.

It may be just me, but as I see it, INT_MAX is a number like any other,
and using it as a mask feels confusing to me.

Would this be ok to you:

/*
 * Context loss count has to be a non-negative value. Clear the sign
 * bit to get a value range from 0 to INT_MAX.
 */
count &= ~(1 << 31);

 Tomi