[Intel-gfx] [bug report] drm/i915/tc: Fix TypeC PHY connect/disconnect logic on ADL-P

[Dan Carpenter]

On Fri, Oct 01, 2021 at 05:20:17PM +0300, Ville Syrjälä wrote:
> On Fri, Oct 01, 2021 at 04:25:35PM +0300, Dan Carpenter wrote:
> > Hello Imre Deak,
> > 
> > This is a semi-automatic email about new static checker warnings.
> > 
> > The patch 3e0abc7661c8: "drm/i915/tc: Fix TypeC PHY 
> > connect/disconnect logic on ADL-P" from Sep 29, 2021, leads to the 
> > following Smatch complaint:
> > 
> >     drivers/gpu/drm/i915/display/intel_ddi.c:4028 intel_ddi_encoder_destroy()
> >     warn: variable dereferenced before check 'dig_port' (see line 4020)
> > 
> > drivers/gpu/drm/i915/display/intel_ddi.c
> >   4019		struct intel_digital_port *dig_port = enc_to_dig_port(to_intel_encoder(encoder));
> >   4020		enum phy phy = intel_port_to_phy(i915, dig_port->base.port);
> >                                                        ^^^^^^^^^^^^^^^^^^^
> > The patch adds a new unchecked dereference.
> > 
> >   4021	
> >   4022		intel_dp_encoder_flush_work(encoder);
> >   4023		if (intel_phy_is_tc(i915, phy))
> >   4024			intel_tc_port_flush_work(dig_port);
> >   4025		intel_display_power_flush_work(i915);
> >   4026	
> >   4027		drm_encoder_cleanup(encoder);
> >   4028		if (dig_port)
> >                     ^^^^^^^^
> > But the existing code checked for NULL.
> 
> That check is nonsense. Feel free to nuke it.

Thanks!  Will do.

regards,
dan carpenter