On Thu, Sep 17, 2020 at 04:50:06PM +0300, Andy Shevchenko wrote:
> On Thu, Sep 17, 2020 at 3:09 PM Thierry Reding <thierry.reding@gmail.com> wrote:
> > On Wed, Sep 09, 2020 at 01:39:59AM +0300, Dmitry Osipenko wrote:
> 
> > Why? All of these functions "return 0 on success or a negative error
> > code on failure", don't they?
> 
> And what is the point of having ' < 0' in all those cases?

It's explicitly checking for the documented error cases. And you'll
occasionally have a function that can return non-zero on success.
Testing for < 0 is the safest way to check for failure in the majority
of cases.

Thierry