[Intel-gfx] [PATCH 1/2] drm/i915: terminate reauth at stream management failure

[Ramalingam C]

On 2020-02-11 at 21:53:55 +0530, Anshuman Gupta wrote:
> On 2020-02-11 at 15:00:01 +0530, Ramalingam C wrote:
> > As per the HDCP2.2 compliance test 1B-10 expectation, when stream
> > management for a repeater fails, we retry thrice and when it fails
> > in all retries, HDCP2.2 reauthentication aborted at kernel.
> > 
> > v2:
> >   seq_num_m++ is extended for steam management failures too.[Anshuman]
> > 
> > Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_hdcp.c | 71 ++++++++++++++---------
> >  1 file changed, 42 insertions(+), 29 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
> > index 4d1a33d13105..fad220d5d105 100644
> > --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> > @@ -1380,7 +1380,7 @@ static int hdcp2_session_key_exchange(struct intel_connector *connector)
> >  }
> >  
> >  static
> > -int hdcp2_propagate_stream_management_info(struct intel_connector *connector)
> > +int _hdcp2_propagate_stream_management_info(struct intel_connector *connector)
> >  {
> >  	struct intel_digital_port *intel_dig_port = intel_attached_dig_port(connector);
> >  	struct intel_hdcp *hdcp = &connector->hdcp;
> > @@ -1406,28 +1406,25 @@ int hdcp2_propagate_stream_management_info(struct intel_connector *connector)
> >  	ret = shim->write_2_2_msg(intel_dig_port, &msgs.stream_manage,
> >  				  sizeof(msgs.stream_manage));
> >  	if (ret < 0)
> > -		return ret;
> > +		goto err_exit;
> >  
> >  	ret = shim->read_2_2_msg(intel_dig_port, HDCP_2_2_REP_STREAM_READY,
> >  				 &msgs.stream_ready, sizeof(msgs.stream_ready));
> >  	if (ret < 0)
> > -		return ret;
> > +		goto err_exit;
> >  
> >  	hdcp->port_data.seq_num_m = hdcp->seq_num_m;
> >  	hdcp->port_data.streams[0].stream_type = hdcp->content_type;
> > -
> >  	ret = hdcp2_verify_mprime(connector, &msgs.stream_ready);
> > -	if (ret < 0)
> > -		return ret;
> >  
> > +err_exit:
> >  	hdcp->seq_num_m++;
> > -
> >  	if (hdcp->seq_num_m > HDCP_2_2_SEQ_NUM_MAX) {
> >  		DRM_DEBUG_KMS("seq_num_m roll over.\n");
> > -		return -1;
> > +		ret = -1;
> >  	}
> >  
> > -	return 0;
> > +	return ret;
> >  }
> >  
> >  static
> > @@ -1492,17 +1489,6 @@ int hdcp2_authenticate_repeater_topology(struct intel_connector *connector)
> >  	return 0;
> >  }
> >  
> > -static int hdcp2_authenticate_repeater(struct intel_connector *connector)
> > -{
> > -	int ret;
> > -
> > -	ret = hdcp2_authenticate_repeater_topology(connector);
> > -	if (ret < 0)
> > -		return ret;
> > -
> > -	return hdcp2_propagate_stream_management_info(connector);
> > -}
> > -
> >  static int hdcp2_authenticate_sink(struct intel_connector *connector)
> >  {
> >  	struct intel_digital_port *intel_dig_port = intel_attached_dig_port(connector);
> > @@ -1537,18 +1523,13 @@ static int hdcp2_authenticate_sink(struct intel_connector *connector)
> >  	}
> >  
> >  	if (hdcp->is_repeater) {
> > -		ret = hdcp2_authenticate_repeater(connector);
> > +		ret = hdcp2_authenticate_repeater_topology(connector);
> >  		if (ret < 0) {
> >  			DRM_DEBUG_KMS("Repeater Auth Failed. Err: %d\n", ret);
> >  			return ret;
> >  		}
> >  	}
> >  
> > -	hdcp->port_data.streams[0].stream_type = hdcp->content_type;
> > -	ret = hdcp2_authenticate_port(connector);
> > -	if (ret < 0)
> > -		return ret;
> > -
> >  	return ret;
> >  }
> >  
> > @@ -1626,14 +1607,46 @@ static int hdcp2_disable_encryption(struct intel_connector *connector)
> >  	return ret;
> >  }
> >  
> > +static int
> > +hdcp2_propagate_stream_management_info(struct intel_connector *connector)
> > +{
> > +	int i, tries = 3, ret;
> > +
> > +	if (!connector->hdcp.is_repeater)
> > +		return 0;
> > +
> > +	for (i = 0; i < tries; i++) {
> > +		ret = _hdcp2_propagate_stream_management_info(connector);
> > +		if (!ret)
> > +			break;
> > +
> > +		DRM_DEBUG_KMS("HDCP2 stream management %d of %d Failed.(%d)\n",
> > +			      i + 1, tries, ret);
> intel_hdcp.c has already replced all DRM_DEBUG_KMD to drm_db_kms() so any new 
> logging need to use drm_dbg_kms().
Thanks for pointing that out. I will replace remaining DRM_DEBUG_KMS
prints too in separate patch. I hope they are not left for a purpose.

-Ram.
> Thanks ,
> Anshuman Gupta.
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> >  static int hdcp2_authenticate_and_encrypt(struct intel_connector *connector)
> >  {
> > +	struct intel_hdcp *hdcp = &connector->hdcp;
> >  	int ret, i, tries = 3;
> >  
> >  	for (i = 0; i < tries; i++) {
> >  		ret = hdcp2_authenticate_sink(connector);
> > -		if (!ret)
> > -			break;
> > +		if (!ret) {
> > +			ret = hdcp2_propagate_stream_management_info(connector);
> > +			if (!ret) {
> > +				hdcp->port_data.streams[0].stream_type =
> > +							hdcp->content_type;
> > +				ret = hdcp2_authenticate_port(connector);
> > +				if (!ret)
> > +					break;
> > +			} else {
> > +				DRM_DEBUG_KMS("HDCP2 stream management failed\n");
> > +				break;
> > +			}
> > +		}
> >  
> >  		/* Clearing the mei hdcp session */
> >  		DRM_DEBUG_KMS("HDCP2.2 Auth %d of %d Failed.(%d)\n",
> > @@ -1642,7 +1655,7 @@ static int hdcp2_authenticate_and_encrypt(struct intel_connector *connector)
> >  			DRM_DEBUG_KMS("Port deauth failed.\n");
> >  	}
> >  
> > -	if (i != tries) {
> > +	if (!ret) {
> >  		/*
> >  		 * Ensuring the required 200mSec min time interval between
> >  		 * Session Key Exchange and encryption.
> > -- 
> > 2.20.1
> >