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 <[email protected]> > > > Signed-off-by: Anshuman Gupta <[email protected]> > > > --- > > > 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. 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 [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
