[PATCH 2/2] drm/i915/hdcp: Fix get remote hdcp capability function

[Borah, Chaitanya Kumar]

> -----Original Message-----
> From: Borah, Chaitanya Kumar
> Sent: Thursday, March 28, 2024 3:56 PM
> To: Kandpal, Suraj <suraj.kandpal at intel.com>; intel-gfx at lists.freedesktop.org
> Subject: RE: [PATCH 2/2] drm/i915/hdcp: Fix get remote hdcp capability
> function
> 
> Hello,
> 
> > -----Original Message-----
> > From: Kandpal, Suraj <suraj.kandpal at intel.com>
> > Sent: Wednesday, March 27, 2024 10:14 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 2/2] drm/i915/hdcp: Fix get remote hdcp capability
> > function
> >
> > HDCP 1.x capability needs to be checked even if setup is not HDCP 2.x
> capable.
> >
> > Fixes: 813cca96e4ac ("drm/i915/hdcp: Add new remote capability check
> > shim
> > function")
> > Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_dp_hdcp.c | 9 ++++-----
> >  1 file changed, 4 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> > b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> > index b98a87883fef..7f52043b0f9f 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> > @@ -688,7 +688,7 @@ int intel_dp_hdcp_get_remote_capability(struct
> > intel_connector *connector,  {
> >  	struct drm_i915_private *i915 = to_i915(connector->base.dev);
> >  	struct drm_dp_aux *aux = &connector->port->aux;
> > -	u8 bcaps;
> > +	u8 bcaps = 0;
> >  	int ret;
> >
> >  	if (!intel_encoder_is_mst(connector->encoder))
> > @@ -696,15 +696,14 @@ int intel_dp_hdcp_get_remote_capability(struct
> > intel_connector *connector,
> >
> >  	ret =  _intel_dp_hdcp2_get_capability(aux, hdcp2_capable);
> >  	if (ret)
> > -		return ret;
> > +		drm_dbg_kms(&i915->drm,
> > +			    "HDCP2 DPCD capability read failed err: %d\n", ret);
> >
> >  	ret = intel_dp_hdcp_read_bcaps(aux, i915, &bcaps);
> > -	if (ret)
> > -		return ret;
> >
> >  	*hdcp_capable = bcaps & DP_BCAPS_HDCP_CAPABLE;
> >
> 
> Let's keep the behavior same for both hdcp_capable and hdcp2_capable in
> case of failure.
> 
> Either assign both of them as false, or not assign anything.
> 

IMO, assigning them false could be a better approach if you don't see any harm in it. It is not great to be dependent on the semantics of them being initialized first.

> Regards
> 
> Chaitanya
> 
> 
> 
> > -	return 0;
> > +	return ret;
> >  }
> >
> >  static const struct intel_hdcp_shim intel_dp_hdcp_shim = {
> > --
> > 2.43.2