[Intel-gfx] [PATCH v3] drm/i915/hdcp: Update CP as per the kernel internal state

[Shankar, Uma]

> -----Original Message-----
> From: Jani Nikula <jani.nikula at intel.com>
> Sent: Tuesday, June 30, 2020 3:30 PM
> To: Gupta, Anshuman <anshuman.gupta at intel.com>; intel-
> gfx at lists.freedesktop.org
> Cc: Shankar, Uma <uma.shankar at intel.com>
> Subject: Re: [Intel-gfx] [PATCH v3] drm/i915/hdcp: Update CP as per the kernel
> internal state
> 
> 
> Uma, is the R-b still valid? It's been a while.

Yeah Jani, the changes look good. Will need a rebase and fresh CI results though.

Regards,
Uma Shankar

> BR,
> Jani.
> 
> 
> On Tue, 30 Jun 2020, Anshuman Gupta <anshuman.gupta at intel.com> wrote:
> > Content Protection property should be updated as per the kernel
> > internal state. Let's say if Content protection is disabled by
> > userspace, CP property should be set to UNDESIRED so that
> > reauthentication will not happen until userspace request it again, but
> > when kernel disables the HDCP due to any DDI disabling sequences like
> > modeset/DPMS operation, kernel should set the property to DESIRED, so
> > that when opportunity arises, kernel will start the HDCP
> > authentication on its own.
> >
> > Somewhere in the line, state machine to set content protection to
> > DESIRED from kernel was broken and IGT coverage was missing for it.
> > This patch fixes it.
> >
> > v2:
> > - Fixing hdcp CP state in connector atomic check function
> >   intel_hdcp_atomic_check(). [Maarten]
> >   This will require to check hdcp->value in intel_hdcp_update_pipe()
> >   in order to avoid enabling hdcp, if it was already enabled.
> >
> > v3:
> > - Rebased.
> >
> > Cc: Ramalingam C <ramalingam.c at intel.com>
> > Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > Reviewed-by: Uma Shankar <uma.shankar at intel.com>
> > Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
> > Link:
> > https://patchwork.freedesktop.org/patch/350962/?series=72664&rev=2 #v1
> > Link:
> > https://patchwork.freedesktop.org/patch/359396/?series=72251&rev=3 #v2
> > ---
> >  drivers/gpu/drm/i915/display/intel_hdcp.c | 27
> > +++++++++++++++++++----
> >  1 file changed, 23 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c
> > b/drivers/gpu/drm/i915/display/intel_hdcp.c
> > index 815b054bb167..0d410652e194 100644
> > --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> > @@ -2086,6 +2086,7 @@ void intel_hdcp_update_pipe(struct
> intel_atomic_state *state,
> >  		(conn_state->hdcp_content_type != hdcp->content_type &&
> >  		 conn_state->content_protection !=
> >  		 DRM_MODE_CONTENT_PROTECTION_UNDESIRED);
> > +	bool desired_and_not_enabled = false;
> >
> >  	/*
> >  	 * During the HDCP encryption session if Type change is requested,
> > @@ -2108,8 +2109,15 @@ void intel_hdcp_update_pipe(struct
> intel_atomic_state *state,
> >  	}
> >
> >  	if (conn_state->content_protection ==
> > -	    DRM_MODE_CONTENT_PROTECTION_DESIRED ||
> > -	    content_protection_type_changed)
> > +	    DRM_MODE_CONTENT_PROTECTION_DESIRED) {
> > +		mutex_lock(&hdcp->mutex);
> > +		/* Avoid enabling hdcp, if it already ENABLED */
> > +		desired_and_not_enabled =
> > +			hdcp->value !=
> DRM_MODE_CONTENT_PROTECTION_ENABLED;
> > +		mutex_unlock(&hdcp->mutex);
> > +	}
> > +
> > +	if (desired_and_not_enabled || content_protection_type_changed)
> >  		intel_hdcp_enable(connector,
> >  				  crtc_state->cpu_transcoder,
> >  				  (u8)conn_state->hdcp_content_type);
> > @@ -2158,6 +2166,19 @@ void intel_hdcp_atomic_check(struct
> drm_connector *connector,
> >  		return;
> >  	}
> >
> > +	crtc_state = drm_atomic_get_new_crtc_state(new_state->state,
> > +						   new_state->crtc);
> > +	/*
> > +	 * Fix the HDCP uapi content protection state in case of modeset.
> > +	 * FIXME: As per HDCP content protection property uapi doc, an uevent()
> > +	 * need to be sent if there is transition from ENABLED->DESIRED.
> > +	 */
> > +	if (drm_atomic_crtc_needs_modeset(crtc_state) &&
> > +	    (old_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED &&
> > +	    new_cp != DRM_MODE_CONTENT_PROTECTION_UNDESIRED))
> > +		new_state->content_protection =
> > +			DRM_MODE_CONTENT_PROTECTION_DESIRED;
> > +
> >  	/*
> >  	 * Nothing to do if the state didn't change, or HDCP was activated since
> >  	 * the last commit. And also no change in hdcp content type.
> > @@ -2170,8 +2191,6 @@ void intel_hdcp_atomic_check(struct drm_connector
> *connector,
> >  			return;
> >  	}
> >
> > -	crtc_state = drm_atomic_get_new_crtc_state(new_state->state,
> > -						   new_state->crtc);
> >  	crtc_state->mode_changed = true;
> >  }
> 
> --
> Jani Nikula, Intel Open Source Graphics Center