On 2020-02-07 at 00:00:13 +0530, Anshuman Gupta wrote: > On 2020-02-06 at 23:06:57 +0530, Ramalingam C wrote: > > On 2020-02-06 at 22:39:28 +0530, Anshuman Gupta wrote: > > > On 2020-02-06 at 22:30:27 +0530, Ramalingam C wrote: > > > > On 2020-02-06 at 20:34:41 +0530, Anshuman Gupta wrote: > > > > > HDCP Repeater initializes seq_num_V to 0 at the beginning of > > > > > hdcp Session i.e. after AKE_init received. > > > > > > > > > > HDCP 2.2 Comp specs 1B-06 test verifies that whether DUT > > > > > considers failures of authentication if the repeater provides a > > > > > non-zero value in seq_num_V in the first, > > > > > RepeaterAuth_Send_ReceiverID_List message after first AKE_Init. > > > > > Fixing this broken test. > > > > Instead of "Fixing the broken test" could we say, we mandate the first > > > > seq_num_v to be zero? in fact i would keep this as commit subject also. > > > > > > > > > > Cc: Ramalingam C <ramalinga...@intel.com> > > > > > Signed-off-by: Anshuman Gupta <anshuman.gu...@intel.com> > > > > > --- > > > > > drivers/gpu/drm/i915/display/intel_display_types.h | 3 +++ > > > > > drivers/gpu/drm/i915/display/intel_hdcp.c | 13 +++++++++++++ > > > > > 2 files changed, 16 insertions(+) > > > > > > > > > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h > > > > > b/drivers/gpu/drm/i915/display/intel_display_types.h > > > > > index 7ae0bc8b80d1..2ae540e986ba 100644 > > > > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h > > > > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h > > > > > @@ -360,6 +360,9 @@ struct intel_hdcp { > > > > > /* HDCP2.2 Encryption status */ > > > > > bool hdcp2_encrypted; > > > > > > > > > > + /* Flag indicate if it is a first ReceiverID_List msg after > > > > > AKE_Init */ > > > > > + bool first_recvid_msg; > > > > This extra flag is not needed, see below comment > > > > > + > > > > > /* > > > > > * Content Stream Type defined by content owner. TYPE0(0x0) > > > > > content can > > > > > * flow in the link protected by HDCP2.2 or HDCP1.4, where as > > > > > TYPE1(0x1) > > > > > diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c > > > > > b/drivers/gpu/drm/i915/display/intel_hdcp.c > > > > > index 4d1a33d13105..3e24a6df503a 100644 > > > > > --- a/drivers/gpu/drm/i915/display/intel_hdcp.c > > > > > +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c > > > > > @@ -1251,6 +1251,8 @@ static int > > > > > hdcp2_authentication_key_exchange(struct intel_connector *connector) > > > > > size_t size; > > > > > int ret; > > > > > > > > > > + hdcp->first_recvid_msg = true; > > > > > + > > > > > /* Init for seq_num */ > > > > > hdcp->seq_num_v = 0; > > > > > hdcp->seq_num_m = 0; > > > > > @@ -1462,6 +1464,16 @@ int > > > > > hdcp2_authenticate_repeater_topology(struct intel_connector > > > > > *connector) > > > > > seq_num_v = > > > > > drm_hdcp_be24_to_cpu((const u8 > > > > > *)msgs.recvid_list.seq_num_v); > > > > > > > > > > + /* > > > > > + * HDCP 2.2 Spec HDMI PAGE 19, DP PAGE 20 > > > > > + * HDCP 2.2 Comp 1B-06 test requires to disable encryption if > > > > > there is > > > > > + * non zero seq_num_V from recevier. > > > > IMHO In commit message this kind of reasoning make sense, but here this > > > > is > > > > not needed. As every line in the file will be as per the spec so we dont > > > > need to call them out. > > > > > + */ > > > > > + if (hdcp->first_recvid_msg && seq_num_v) { > > > > if (!hdcp->seq_num_v && seq_num_v) { > > > > > > > > IMO This is all we need it. > > > I had tried this as my first solution, eventually this fill the link > > > integrity check, see below. > > > > > > > > -Ram > > > > > + drm_dbg_kms(&dev_priv->drm, "Non zero Seq_num_v at > > > > > beginning of HDCP Session\n"); > > > > > + return -EINVAL; > > > > > + } > > > > > + > > > > > if (seq_num_v < hdcp->seq_num_v) { > > > > > /* Roll over of the seq_num_v from repeater. > > > > > Reauthenticate. */ > > > > > DRM_DEBUG_KMS("Seq_num_v roll over.\n"); > > > > > @@ -1484,6 +1496,7 @@ int hdcp2_authenticate_repeater_topology(struct > > > > > intel_connector *connector) > > > > > return ret; > > > > > > > > > > hdcp->seq_num_v = seq_num_v; > > > seq_num_v will be zero for first session, which left hdcp->seq_num_v to > > > zero and that will > > > fail the link intergrity check as at during link intergrity check > > > seq_num_v will be non-zero, > > > this happens during 1B-09, when repeater topolgy changes due to > > > Roll over of seq_num_v. > > > > topology update should increment the seq_num_v which will make it > than > > hdcp->seq_num_v. How roll over happens? And at every AKE start we init > > hdcp->seq_num_v to 0. > > > > So please elaborate the failure scenario. > Please refer to HDCP 2.2 spec page page 44 Step 1-B-09 > STEP 1B-09-01 > -> TE sets seq_num_V to 0xFFFFFFh Is it possible to randomly set seq_num_v to 0xFFFFFFh after 0? thought it is getting incremented by 1 for every topology change. > -> TE simulate disconnect of active downstream device by decrementing > DEVICE_COUNT > *As I understand above will assert the READY bit that will detect as topology > change and will make a call > to hdcp2_authenticate_repeater_topology() and there it will fail for > if (!hdcp->seq_num_v && seq_num_v) conidiation, and test will fail here > itself. possible if the TE change the seq_num_v from 0 to ffffffh directly. Need to check whether that is ok to do?
> -> DUT sends RepeaterAuth_Send_Ack message > STEP 1B-09-02 > -> TE will set seq_num_V to 0x000 to indicate Roll Over. > > Please correct me if i am wrong here. if not the hdcp->seq_num_v, you can use hdcp->value which will be ENABLED for repeated topology change or you can use hdcp->hdcp2_encrypted which will be true in above roll over case. Thanks, Ram. > > Thanks , > Anshuman Gupta. > > > > > Ram. > > > Thanks , > > > Anshuman Gupta. > > > > > > > > + hdcp->first_recvid_msg = false; > > > > > ret = shim->write_2_2_msg(intel_dig_port, &msgs.rep_ack, > > > > > sizeof(msgs.rep_ack)); > > > > > if (ret < 0) > > > > > -- > > > > > 2.24.0 > > > > > _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx