[Intel-gfx] [PATCH] drm/i915/ddi: Fix i2c_adapter assignment

[Kandpal, Suraj]

> Subject: Re: [Intel-gfx] [PATCH] drm/i915/ddi: Fix i2c_adapter assignment
> 
> On Thu, 05 Oct 2023, Ville Syrjälä <ville.syrjala at linux.intel.com> wrote:
> > On Thu, Oct 05, 2023 at 12:12:58PM +0530, Suraj Kandpal wrote:
> >> i2c_adapter is being assigned using intel_connector even before the
> >> NULL check occurs and even though it shouldn't be a problem lets just
> >> clean this up as logically it does not make sense to check the
> >> connector for NULL but dereference it before that.
> >>
> >> Fixes: e046d1562491 ("drm/i915/hdmi: Use connector->ddc everwhere")
> >>
> >> Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> >> ---
> >>  drivers/gpu/drm/i915/display/intel_ddi.c | 4 +++-
> >>  1 file changed, 3 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
> >> b/drivers/gpu/drm/i915/display/intel_ddi.c
> >> index 4668de45d6fe..6b658faf1fc3 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> >> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> >> @@ -4326,7 +4326,7 @@ static int intel_hdmi_reset_link(struct
> intel_encoder *encoder,
> >>  	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> >>  	struct intel_hdmi *hdmi = enc_to_intel_hdmi(encoder);
> >>  	struct intel_connector *connector = hdmi->attached_connector;
> >> -	struct i2c_adapter *ddc = connector->base.ddc;
> >> +	struct i2c_adapter *ddc;
> >>  	struct drm_connector_state *conn_state;
> >>  	struct intel_crtc_state *crtc_state;
> >>  	struct intel_crtc *crtc;
> >> @@ -4336,6 +4336,8 @@ static int intel_hdmi_reset_link(struct
> intel_encoder *encoder,
> >>  	if (!connector || connector->base.status !=
> connector_status_connected)
> >>  		return 0;
> >
> > The connector is never NULL here. So the check is just nonsense.
> 
> Yeah I'd rather remove that. Leaving it in makes people (and static analyzers,
> apprently) think it could be NULL, and that leads to more what ifs.
> 
> BR,
> Jani.
> 

Makes sense will remove the connector check instead of moving the assignment around

Regards,
Suraj Kandpal

> >
> >>
> >> +	ddc = connector->base.ddc;
> >> +
> >>  	ret = drm_modeset_lock(&dev_priv-
> >drm.mode_config.connection_mutex,
> >>  			       ctx);
> >>  	if (ret)
> >> --
> >> 2.25.1
> 
> --
> Jani Nikula, Intel