Re: [GIT PULL FOR v4.18] R-Car VSP1 TLB optimisation

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Dan,

Thank you for your quick reply.

On Monday, 28 May 2018 13:20:49 EEST Dan Carpenter wrote:
> On Mon, May 28, 2018 at 11:28:41AM +0300, Laurent Pinchart wrote:
> > and I still get the same warning. I had to write the following (which is
> > obviously not correct) to silence the warning.
> > 
> >         if (pipe->num_inputs > 2)
> >                 brx = &vsp1->bru->entity;
> >         else if (pipe->brx)
> >                 brx = pipe->brx;
> >         else if (!vsp1->bru->entity.pipe)
> >                 brx = &vsp1->bru->entity;
> >         else {
> >                 (void)vsp1->brs->entity;
> >                 brx = &vsp1->brs->entity;
> >         }
> > 
> > Both the (void)vsp1->brs->entity and the removal of the !drm_pipe->
> > force_brx_release were needed, any of those on its own didn't fix the
> > problem.
> 
> The problem in this case is the first "brx = &vsp1->bru->entity;".
> Smatch assumes &vsp1->bru->entity can be == to pipe->brx and NULL.

Why does smatch assume that &vsp1->bru->entity can be NULL, when the previous 
line dereferences vsp1->bru ?

> Adding a "(void)vsp1->bru->entity;" on that path will silence the
> warning (hopefully).

-- 
Regards,

Laurent Pinchart