[PATCH] drm/i915/display: Initalizalize capability variables

[Kandpal, Suraj]

> -----Original Message-----
> From: Borah, Chaitanya Kumar <chaitanya.kumar.borah at intel.com>
> Sent: Wednesday, March 27, 2024 9:32 AM
> To: Kandpal, Suraj <suraj.kandpal at intel.com>; intel-gfx at lists.freedesktop.org
> Subject: RE: [PATCH] drm/i915/display: Initalizalize capability variables
> 
> 
> 
> > -----Original Message-----
> > From: Kandpal, Suraj <suraj.kandpal at intel.com>
> > Sent: Wednesday, March 27, 2024 9:06 AM
> > To: Borah, Chaitanya Kumar <chaitanya.kumar.borah at intel.com>; intel-
> > gfx at lists.freedesktop.org
> > Subject: RE: [PATCH] drm/i915/display: Initalizalize capability
> > variables
> >
> > > Hello Suraj,
> > >
> > > > -----Original Message-----
> > > > From: Kandpal, Suraj <suraj.kandpal at intel.com>
> > > > Sent: Tuesday, March 26, 2024 10:45 AM
> > > > To: intel-gfx at lists.freedesktop.org
> > > > Cc: Borah, Chaitanya Kumar <chaitanya.kumar.borah at intel.com>;
> > > > Kandpal, Suraj <suraj.kandpal at intel.com>
> > > > Subject: [PATCH] drm/i915/display: Initalizalize capability
> > > > variables
> > >
> > > Typo: Initialize
> > >
> >
> > Sure will fix
> >
> > > > Initialize HDCP capability variables to false to avoid UBSAN
> > > > warning in boolean value.
> > > >
> > >
> > > I can see a case where hdcp_cap remains unassigned in case
> > > intel_dp_hdcp_get_remote_capability() returns without assigning it a
> value.
> > >
> > > Is that intended/expected?
> > >
> >
> > That is not intentional but this patch makes sure hdcp_capable will be
> > false when this function gets called.
> >
> 
> This patch makes sense for sure but what I am getting at is if UBSAN is
> revealing a bug in our code.
> 
> intel_dp_hdcp_get_remote_capability() returns if
> _intel_dp_hdcp2_get_capability() fails. In that case we never check for hdcp
> 1.4 capability.
> If a remote sink can be hdcp 1.4 capable but not hdcp 2 capable, this logic is
> problematic.

True let me add a patch that fixes that too.
 Regards,
Suraj Kandpal
> 
> Regards
> 
> Chaitanya
> 
> > Regards,
> > Suraj Kandpal
> >
> > > Regards
> > >
> > > Chaitanya
> > >
> > > > Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> > > > ---
> > > >  drivers/gpu/drm/i915/display/intel_display_debugfs.c | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > > > b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > > > index b99c024b0934..95d14dab089e 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > > > @@ -191,7 +191,7 @@ static void intel_hdcp_info(struct seq_file *m,
> > > >  			    struct intel_connector *intel_connector,
> > > >  			    bool remote_req)
> > > >  {
> > > > -	bool hdcp_cap, hdcp2_cap;
> > > > +	bool hdcp_cap = false, hdcp2_cap = false;
> > > >
> > > >  	if (!intel_connector->hdcp.shim) {
> > > >  		seq_puts(m, "No Connector Support");
> > > > --
> > > > 2.43.2