[Intel-gfx] [PATCH v4 15/16] drm/i915/hdcp: Support for HDCP 2.2 MST shim callbacks
Ramalingam C
ramalingam.c at intel.com
Mon Nov 9 08:38:31 UTC 2020
On 2020-11-09 at 11:06:24 +0530, Anshuman Gupta wrote:
> On 2020-11-06 at 16:42:21 +0530, Ramalingam C wrote:
> > On 2020-11-06 at 14:57:25 +0530, Ramalingam C wrote:
> > > On 2020-11-03 at 11:57:00 +0530, Anshuman Gupta wrote:
> > > > Add support for HDCP 2.2 DP MST shim callback.
> > > > This adds existing DP HDCP shim callback for Link Authentication
> > > > and Encryption and HDCP 2.2 stream encryption
> > > > callback.
> > > >
> > > > v2:
> > > > Added a WARN_ON() instead of drm_err. [Uma]
> > > > Cosmetic changes. [Uma]
> > >
> > > Reviewed-by: Ramalingam C <ramalingam.c at intel.com>
> > I think we can improvise further here.
> >
> > > >
> > > > Cc: Ramalingam C <ramalingam.c at intel.com>
> > > > Reviewed-by: Uma Shankar <uma.shankar at intel.com>
> > > > Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
> > > > ---
> > > > .../drm/i915/display/intel_display_types.h | 4 +
> > > > drivers/gpu/drm/i915/display/intel_dp_hdcp.c | 80 +++++++++++++++++--
> > > > 2 files changed, 76 insertions(+), 8 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > index dfb5be64e03a..4cbb151ff3cf 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > @@ -374,6 +374,10 @@ struct intel_hdcp_shim {
> > > > int (*config_stream_type)(struct intel_digital_port *dig_port,
> > > > bool is_repeater, u8 type);
> > > >
> > > > + /* Enable/Disable HDCP 2.2 stream encryption on DP MST Transport Link */
> > > > + int (*stream_2_2_encryption)(struct intel_digital_port *dig_port,
> > > > + bool enable);
> > > > +
> > > > /* HDCP2.2 Link Integrity Check */
> > > > int (*check_2_2_link)(struct intel_digital_port *dig_port,
> > > > struct intel_connector *connector);
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> > > > index 4be61e7fde4e..35c1543fe0e2 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> > > > @@ -698,18 +698,14 @@ intel_dp_mst_hdcp_stream_encryption(struct intel_digital_port *dig_port,
> > > > return 0;
> > > > }
> > > >
> > > > -static
> > > > -bool intel_dp_mst_hdcp_check_link(struct intel_digital_port *dig_port,
> > > > - struct intel_connector *connector)
> > > > +static bool intel_dp_mst_get_qses_status(struct intel_digital_port *dig_port,
> > > > + struct intel_connector *connector)
> > > > {
> > > > struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> > > > - struct intel_dp *intel_dp = &dig_port->dp;
> > > > struct drm_dp_query_stream_enc_status_ack_reply reply;
> > > > + struct intel_dp *intel_dp = &dig_port->dp;
> > > > int ret;
> > > >
> > > > - if (!intel_dp_hdcp_check_link(dig_port, connector))
> > > > - return false;
> > > > -
> > > > ret = drm_dp_send_query_stream_enc_status(&intel_dp->mst_mgr,
> > > > connector->port, &reply);
> > > > if (ret) {
> > > > @@ -722,6 +718,69 @@ bool intel_dp_mst_hdcp_check_link(struct intel_digital_port *dig_port,
> > > > return reply.auth_completed && reply.encryption_enabled;
> > > > }
> > > >
> > > > +static
> > > > +bool intel_dp_mst_hdcp_check_link(struct intel_digital_port *dig_port,
> > > > + struct intel_connector *connector)
> > > > +{
> > > > + if (!intel_dp_hdcp_check_link(dig_port, connector))
> > > > + return false;
> > > > +
> > > > + return intel_dp_mst_get_qses_status(dig_port, connector);
> > > > +}
> > > > +
> > > > +static int
> > > > +intel_dp_mst_hdcp2_stream_encryption(struct intel_digital_port *dig_port,
> > > > + bool enable)
> > > > +{
> > > > + struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> > > > + struct hdcp_port_data *data = &dig_port->port_data;
> > > > + struct intel_dp *dp = &dig_port->dp;
> > > > + struct intel_hdcp *hdcp = &dp->attached_connector->hdcp;
> > > > + enum port port = dig_port->base.port;
> > > > + /* HDCP2.x register uses stream transcoder */
> > > > + enum transcoder cpu_transcoder = hdcp->stream_transcoder;
> > > > + int ret;
> > > > +
> > > > + drm_WARN_ON(&i915->drm, enable &&
> > > > + !!(intel_de_read(i915, HDCP2_AUTH_STREAM(i915, cpu_transcoder, port))
> > > > + & AUTH_STREAM_TYPE) != data->streams[0].stream_type);
> > > > +
> > > > + ret = intel_dp_mst_toggle_hdcp_stream_select(dig_port, enable);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + /* Wait for encryption confirmation */
> > > > + if (intel_de_wait_for_register(i915,
> > > > + HDCP2_STREAM_STATUS(i915, cpu_transcoder, port),
> > > > + STREAM_ENCRYPTION_STATUS,
> > > > + enable ? STREAM_ENCRYPTION_STATUS : 0,
> > > > + HDCP_ENCRYPT_STATUS_CHANGE_TIMEOUT_MS)) {
> > > > + drm_err(&i915->drm, "Timed out waiting for stream encryption %s\n",
> > > > + enable ? "enabled" : "disabled");
> > > > + return -ETIMEDOUT;
> > > > + }
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > > > +/*
> > > > + * DP v2.0 I.3.3 ignore the stream signature L' in QSES reply msg reply.
> > > > + * I.3.5 MST source device may use a QSES msg to query downstream status
> > > > + * for a particular stream.
> > > > + */
> > > > +static
> > > > +int intel_dp_mst_hdcp2_check_link(struct intel_digital_port *dig_port,
> > > > + struct intel_connector *connector)
> > > > +{
> >
> > Since on MST topology only for connector with mst transcoder hdcp
> > authentication will be done. all other connectors' hdcp enable are just
> > enabling the stream encryption.
> One correction here, driver will authenticate the link and enable the encryption
> on the link for the first HDCP request form user space(user space can ask to enable
> HDCP on any stream first as it is not aware of master/slave), so driver doesn't
> need to distinguish between master trascoder and slave transcoder.
> When link is encrypted driver will enable the stream encryption for the stream
> which has asked for it.
> >
> > So the check link is needed for the port which has done the real hdcp
> > authentication. other hdcp instances need the qses check for the stream
> > encryption status check.
> Yes this can be optimized, check link required for the connector
> which has involved with link authentication and encryption,
> i would prefer to use hdcp->is_repeater for that becuase this will be true
> only for the connector which has involved with link authentication and encryption.
May be we need to comment on why this is_reepeater is checked at this
point..
> >
> > this can be combined schedule the check_link{1.4, 2.2) work only for the
> > connector with mst transcoder. and in that check_link work, do the qses
> > check for all the connectors on that mst topology and then do the real
> > check_link for the mst port alone. This way we avoid the three to four
> > instance of check link delayed work with one.
> I think it would be the better way to skip the link check for the connector
> which has hdcp->is_repeater false and limit those only with QSES check
> in check_2_2_link shim callback. This will abstract this from intel_hdcp.c
> by just keeping in shim callbacks. Please provide your opinion ?
>
> HDCP 1.4 will go through link authentication and encryption for each connector
> in DP MST topology, so i belive let it call the check_link for each connector
> along with QSES check.
With this delayed work count is not going down. If there is any concern
in future, we could revisit this decision. Otherwise this looks fine
now.
-Ram
>
> Thanks,
> Anshuman Gupta.
> >
> >
> > -Ram
> > > > + int ret;
> > > > +
> > > > + ret = intel_dp_hdcp2_check_link(dig_port, connector);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + return intel_dp_mst_get_qses_status(dig_port, connector) ? 0 : -EINVAL;
> > > > +}
> > > > +
> > > > static const struct intel_hdcp_shim intel_dp_mst_hdcp_shim = {
> > > > .write_an_aksv = intel_dp_hdcp_write_an_aksv,
> > > > .read_bksv = intel_dp_hdcp_read_bksv,
> > > > @@ -735,7 +794,12 @@ static const struct intel_hdcp_shim intel_dp_mst_hdcp_shim = {
> > > > .stream_encryption = intel_dp_mst_hdcp_stream_encryption,
> > > > .check_link = intel_dp_mst_hdcp_check_link,
> > > > .hdcp_capable = intel_dp_hdcp_capable,
> > > > -
> > > > + .write_2_2_msg = intel_dp_hdcp2_write_msg,
> > > > + .read_2_2_msg = intel_dp_hdcp2_read_msg,
> > > > + .config_stream_type = intel_dp_hdcp2_config_stream_type,
> > > > + .stream_2_2_encryption = intel_dp_mst_hdcp2_stream_encryption,
> > > > + .check_2_2_link = intel_dp_mst_hdcp2_check_link,
> > > > + .hdcp_2_2_capable = intel_dp_hdcp2_capable,
> > > > .protocol = HDCP_PROTOCOL_DP,
> > > > };
> > > >
> > > > --
> > > > 2.26.2
> > > >
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> > > Intel-gfx at lists.freedesktop.org
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