Re: [PATCH 2/7] drm/i915/hdcp: HDCP Capability for the downstream device

["Nautiyal, Ankit K" <ankit.k.nautiyal@xxxxxxxxx>]

On 1/27/2024 12:14 PM, Kandpal, Suraj wrote:
> =
> > On 1/24/2024 6:50 PM, Nautiyal, Ankit K wrote:
> > > On 1/12/2024 1:11 PM, Suraj Kandpal wrote:
> > > > Currently we are only checking capability of remote device and not
> > > > immediate downstream device but during capability check we need are
> > > > concerned with only the HDCP capability of downstream device.
> > > > During i915_display_info reporting we need HDCP Capability for both
> > > > the monitors and downstream branch device if any this patch adds that.
> > >
> > > I agree cases where MST hub/docker and sink are of different
> > > capabilities, this creates a confusion.
> > >
> > > with this change, perhaps kms_content_protection IGT can also be
> > > changed to check for MST hub's capability.
> > >
> > > Only thing is that for hdmi the 'remote_req' doesnt make sense.
> > Instead of changing the hdcp_2_2_capable can we just have a separate
> > function for intel_dp_remote_hdcp2_capable(), which uses aux =
> > &connector->port->aux.
> Yes I agree about the hdmi has a argument it wont use but I went with the lesser
> Of the two evils . If I went with the approach suggested the problem would be that
> debug fs calls intel_hdcp2_capable which has other checks for mei, gsc and If HW supports
> hdcp2 or not so all this would also have to be put in this function intel_dp_remote_hdcp2_capable()
> which I feel would create much more of a mess
>
> Regards,
> Suraj Kandpal

I see for HDCP1.4 also we need to have a separate functions if we want 
to get correct HDCP capability for remote sinks.

I think lets not change existing hdcp_2_capable function. IMHO it would 
be better to have another shim function for hdcp capabilities of remote 
sink.


Regards,

Ankit

> > The common code for reading HDCP2_2 Rx caps can be pulled out in a
> > separate function, which we can call only in case of MST when we read
> > remote.
> >
> > Also we might need to have similar thing for HDCP1.4.
> >
> >
> > Regards,
> >
> > Ankit
> >
> >
> > > > Signed-off-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
> > > > ---
> > > >    .../drm/i915/display/intel_display_debugfs.c  | 19
> > > > +++++++++++++++----
> > > >    .../drm/i915/display/intel_display_types.h    |  2 +-
> > > >    drivers/gpu/drm/i915/display/intel_dp_hdcp.c  |  4 ++--
> > > >    drivers/gpu/drm/i915/display/intel_hdcp.c     |  6 +++---
> > > >    drivers/gpu/drm/i915/display/intel_hdcp.h     |  2 +-
> > > >    drivers/gpu/drm/i915/display/intel_hdmi.c     |  2 +-
> > > >    6 files changed, 23 insertions(+), 12 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > > > b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > > > index d951edb36687..457f13357fad 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > > > @@ -210,7 +210,8 @@ static void intel_panel_info(struct seq_file *m,
> > > >    }
> > > >      static void intel_hdcp_info(struct seq_file *m,
> > > > -                struct intel_connector *intel_connector)
> > > > +                struct intel_connector *intel_connector,
> > > > +                bool remote_req)
> > > >    {
> > > >        bool hdcp_cap, hdcp2_cap;
> > > >    @@ -220,7 +221,7 @@ static void intel_hdcp_info(struct seq_file *m,
> > > >        }
> > > >          hdcp_cap = intel_hdcp_capable(intel_connector);
> > > > -    hdcp2_cap = intel_hdcp2_capable(intel_connector);
> > > > +    hdcp2_cap = intel_hdcp2_capable(intel_connector, remote_req);
> > > >          if (hdcp_cap)
> > > >            seq_puts(m, "HDCP1.4 ");
> > > > @@ -307,7 +308,12 @@ static void intel_connector_info(struct seq_file
> > > > *m,
> > > >        }
> > > >          seq_puts(m, "\tHDCP version: ");
> > > > -    intel_hdcp_info(m, intel_connector);
> > > > +    intel_hdcp_info(m, intel_connector, true);
> > > > +
> > > > +    if (intel_encoder_is_mst(encoder)) {
> > > > +        seq_puts(m, "\tHDCP Branch Device version: ");
> > > > +        intel_hdcp_info(m, intel_connector, false);
> > > > +    }
> > > >          seq_printf(m, "\tmax bpc: %u\n",
> > > > connector->display_info.bpc);
> > > >    @@ -1153,7 +1159,12 @@ static int
> > > > i915_hdcp_sink_capability_show(struct seq_file *m, void *data)
> > > >          seq_printf(m, "%s:%d HDCP version: ", connector->base.name,
> > > >               connector->base.base.id);
> > > > -    intel_hdcp_info(m, connector);
> > > > +    intel_hdcp_info(m, connector, true);
> > > > +
> > > > +    if (intel_encoder_is_mst(connector->encoder)) {
> > > > +        seq_puts(m, "\tHDCP Branch Device version: ");
> > >
> > > Perhaps MST HUB HDCP version?
> > >
> > >
> > > > +        intel_hdcp_info(m, connector, false);
> > > > +    }
> > > >      out:
> > > > drm_modeset_unlock(&i915->drm.mode_config.connection_mutex);
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > index ae2e8cff9d69..aa559598f049 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > @@ -507,7 +507,7 @@ struct intel_hdcp_shim {
> > > >          /* Detects whether sink is HDCP2.2 capable */
> > > >        int (*hdcp_2_2_capable)(struct intel_connector *connector,
> > > > -                bool *capable);
> > > > +                bool *capable, bool remote_req);
> > > >          /* Write HDCP2.2 messages */
> > > >        int (*write_2_2_msg)(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 bec49061b2e1..90b027ba3302 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> > > > @@ -649,13 +649,13 @@ int intel_dp_hdcp2_check_link(struct
> > > > intel_digital_port *dig_port,
> > > >      static
> > > >    int intel_dp_hdcp2_capable(struct intel_connector *connector,
> > > > -               bool *capable)
> > > > +               bool *capable, bool remote_req)
> > > >    {
> > > >        struct drm_dp_aux *aux;
> > > >        u8 rx_caps[3];
> > > >        int ret;
> > > >    -    aux = intel_dp_hdcp_get_aux(connector, true);
> > > > +    aux = intel_dp_hdcp_get_aux(connector, remote_req);
> > > Inline with the comments on the previous patch, this would also be
> > > required to change.
> > >
> > > Otherwise the patch looks good to me.
> > >
> > >
> > > Regards,
> > >
> > > Ankit
> > >
> > > >          *capable = false;
> > > >        ret = drm_dp_dpcd_read(aux,
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c
> > > > b/drivers/gpu/drm/i915/display/intel_hdcp.c
> > > > index c3e692e7f790..b88a4713e6a8 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> > > > @@ -161,7 +161,7 @@ bool intel_hdcp_capable(struct intel_connector
> > > > *connector)
> > > >    }
> > > >      /* Is HDCP2.2 capable on Platform and Sink */ -bool
> > > > intel_hdcp2_capable(struct intel_connector *connector)
> > > > +bool intel_hdcp2_capable(struct intel_connector *connector, bool
> > > > remote_req)
> > > >    {
> > > >        struct drm_i915_private *i915 = to_i915(connector->base.dev);
> > > >        struct intel_hdcp *hdcp = &connector->hdcp; @@ -186,7 +186,7 @@
> > > > bool intel_hdcp2_capable(struct intel_connector
> > > > *connector)
> > > >        mutex_unlock(&i915->display.hdcp.hdcp_mutex);
> > > >          /* Sink's capability for HDCP2.2 */
> > > > -    hdcp->shim->hdcp_2_2_capable(connector, &capable);
> > > > +    hdcp->shim->hdcp_2_2_capable(connector, &capable, remote_req);
> > > >          return capable;
> > > >    }
> > > > @@ -2374,7 +2374,7 @@ static int _intel_hdcp_enable(struct
> > > > intel_atomic_state *state,
> > > >         * Considering that HDCP2.2 is more secure than HDCP1.4, If the
> > > > setup
> > > >         * is capable of HDCP2.2, it is preferred to use HDCP2.2.
> > > >         */
> > > > -    if (intel_hdcp2_capable(connector)) {
> > > > +    if (intel_hdcp2_capable(connector, false)) {
> > > >            ret = intel_hdcp_set_streams(dig_port, state);
> > > >            if (!ret) {
> > > >                ret = _intel_hdcp2_enable(connector); diff --git
> > > > a/drivers/gpu/drm/i915/display/intel_hdcp.h
> > > > b/drivers/gpu/drm/i915/display/intel_hdcp.h
> > > > index a9c784fd9ba5..72268e593cec 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_hdcp.h
> > > > +++ b/drivers/gpu/drm/i915/display/intel_hdcp.h
> > > > @@ -39,7 +39,7 @@ void intel_hdcp_update_pipe(struct
> > > > intel_atomic_state *state,
> > > >                    const struct drm_connector_state *conn_state);
> > > >    bool is_hdcp_supported(struct drm_i915_private *i915, enum port
> > > > port);
> > > >    bool intel_hdcp_capable(struct intel_connector *connector); -bool
> > > > intel_hdcp2_capable(struct intel_connector *connector);
> > > > +bool intel_hdcp2_capable(struct intel_connector *connector, bool
> > > > remote_req);
> > > >    void intel_hdcp_component_init(struct drm_i915_private *i915);
> > > >    void intel_hdcp_component_fini(struct drm_i915_private *i915);
> > > >    void intel_hdcp_cleanup(struct intel_connector *connector); diff
> > > > --git a/drivers/gpu/drm/i915/display/intel_hdmi.c
> > > > b/drivers/gpu/drm/i915/display/intel_hdmi.c
> > > > index 7020e5806109..d7feef05bc47 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_hdmi.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
> > > > @@ -1733,7 +1733,7 @@ int intel_hdmi_hdcp2_check_link(struct
> > > > intel_digital_port *dig_port,
> > > >      static
> > > >    int intel_hdmi_hdcp2_capable(struct intel_connector *connector,
> > > > -                 bool *capable)
> > > > +                 bool *capable, bool remote_req)
> > >
> > > >    {
> > > >        struct intel_digital_port *dig_port =
> > > > intel_attached_dig_port(connector);
> > > >        u8 hdcp2_version;