[Intel-gfx] [PATCH 1/4] drm/i915/hdcp: Update CP as per the kernel internal state

[Maarten Lankhorst]

Op 05-02-2020 om 06:07 schreef Anshuman Gupta:
> On 2020-01-28 at 21:45:45 +0530, Anshuman Gupta wrote:
> Hi Jani ,
> As per my understanding intel_hdcp_atomic_check() is not sufficient to
> fix the broken hdcp uapi state, as the state fixup required in case
> of modeset.
> If you do not have any concern, can we continue with the patch.
> Thanks,
> Anshuman Gupta.

Hey,

In case of a modeset, don't we always call atomic_check() on the connector, either before or after?

Should be fine to fixup there then?

>> On 2020-01-28 at 21:14:44 +0530, Anshuman Gupta wrote:
>>> On 2020-01-28 at 16:19:31 +0200, Jani Nikula wrote:
>>>> On Tue, 28 Jan 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.
>>>>> IGT patch to catch further regression on this features is being
>>>>> worked upon.
>>>>>
>>>>> CC: Ramalingam C <ramalingam.c at intel.com>
>>>>> Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
>>>>> ---
>>>>>  drivers/gpu/drm/i915/display/intel_display.c |  4 +++
>>>>>  drivers/gpu/drm/i915/display/intel_hdcp.c    | 26 ++++++++++++++++++++
>>>>>  drivers/gpu/drm/i915/display/intel_hdcp.h    |  2 ++
>>>>>  3 files changed, 32 insertions(+)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
>>>>> index da5266e76738..934cdf1f1858 100644
>>>>> --- a/drivers/gpu/drm/i915/display/intel_display.c
>>>>> +++ b/drivers/gpu/drm/i915/display/intel_display.c
>>>>> @@ -14595,6 +14595,10 @@ static int intel_atomic_check(struct drm_device *dev,
>>>>>  		goto fail;
>>>>>  
>>>>>  	if (any_ms) {
>>>>> +		/*
>>>>> +		 * When there is modeset fix the hdcp uapi CP state.
>>>>> +		 */
>>>>> +		intel_hdcp_post_need_modeset_check(state);
>>>>>  		ret = intel_modeset_checks(state);
>>>>>  		if (ret)
>>>>>  			goto fail;
>>>>> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
>>>>> index 0fdbd39f6641..be083136eee2 100644
>>>>> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
>>>>> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
>>>>> @@ -2074,6 +2074,32 @@ void intel_hdcp_atomic_check(struct drm_connector *connector,
>>>>>  	crtc_state->mode_changed = true;
>>>>>  }
>>>>>  
>>>>> +/**
>>>>> + * intel_hdcp_post_need_modeset_check.
>>>>> + * @state: intel atomic state.
>>>>> + *
>>>>> + * This function fix the HDCP uapi state when hdcp disabling initiated from
>>>>> + * modeset DDI disabling sequence. It updates uapi CP state from ENABLED to
>>>>> + * DESIRED so that HDCP uapi state can be restored as per HDCP Auth state.
>>>>> + * This function should be called only in case of 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.
>>>>> + */
>>>>> +void intel_hdcp_post_need_modeset_check(struct intel_atomic_state *state)
>>>>> +{
>>>>> +	struct drm_connector *connector;
>>>>> +	struct drm_connector_state *old_state;
>>>>> +	struct drm_connector_state *new_state;
>>>>> +	int i;
>>>>> +
>>>>> +	for_each_oldnew_connector_in_state(&state->base, connector, old_state,
>>>>> +					   new_state, i) {
>>>>> +		if (old_state->content_protection == DRM_MODE_CONTENT_PROTECTION_ENABLED &&
>>>>> +		    new_state->content_protection != DRM_MODE_CONTENT_PROTECTION_UNDESIRED)
>>>>> +			new_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
>>>>> +	}
>>>>> +}
>>>>> +
>>>> Why does this feel like duplication of what you already have in
>>>> intel_hdcp_atomic_check()?
>>> intel_hdcp_atomic_check() have checks that for disconnected connector and it doesn't look for 
>> typo here, "intel_hdcp_atomic_check() checks that for disconnected connector and it doesn't check for new state shouldn't be UNDESIRED" 
>>> old state, that is not sufficient to fix the hdcp CP uapi state, it need to be fix only in case of
>>> modeset, Later on a fastset check can disable the modeset and we would endup calling intel_hdcp_enable
>>> while hdcp is already enabled. That is the reason i think we would require a new API to
>>> fix the uapi state.
>>> Thanks ,
>>> Anshuman Gupta.
>>>> BR,
>>>> Jani.
>>>>
>>>>
>>>>>  /* Handles the CP_IRQ raised from the DP HDCP sink */
>>>>>  void intel_hdcp_handle_cp_irq(struct intel_connector *connector)
>>>>>  {
>>>>> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.h b/drivers/gpu/drm/i915/display/intel_hdcp.h
>>>>> index f3c3272e712a..7bf46bc3c348 100644
>>>>> --- a/drivers/gpu/drm/i915/display/intel_hdcp.h
>>>>> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.h
>>>>> @@ -13,6 +13,7 @@
>>>>>  struct drm_connector;
>>>>>  struct drm_connector_state;
>>>>>  struct drm_i915_private;
>>>>> +struct intel_atomic_state;
>>>>>  struct intel_connector;
>>>>>  struct intel_hdcp_shim;
>>>>>  enum port;
>>>>> @@ -21,6 +22,7 @@ enum transcoder;
>>>>>  void intel_hdcp_atomic_check(struct drm_connector *connector,
>>>>>  			     struct drm_connector_state *old_state,
>>>>>  			     struct drm_connector_state *new_state);
>>>>> +void intel_hdcp_post_need_modeset_check(struct intel_atomic_state *state);
>>>>>  int intel_hdcp_init(struct intel_connector *connector,
>>>>>  		    const struct intel_hdcp_shim *hdcp_shim);
>>>>>  int intel_hdcp_enable(struct intel_connector *connector,
>>>> -- 
>>>> Jani Nikula, Intel Open Source Graphics Center
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