Re: [PATCH v10 07/40] drm/i915: hdcp1.4 CP_IRQ handling and SW encryption tracking

C, Ramalingam
2019-02-04T14:43:54Z

On 2/4/2019 7:39 PM, Shankar, Uma wrote:
>
>> -----Original Message-----
>> From: C, Ramalingam
>> Sent: Thursday, January 31, 2019 12:29 PM
>> To: intel-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org;
>> daniel.vetter@ffwll.ch; Winkler, Tomas <tomas.winkler@intel.com>; Shankar,
>> Uma <uma.shankar@intel.com>
>> Cc: C, Ramalingam <ramalingam.c@intel.com>
>> Subject: [PATCH v10 07/40] drm/i915: hdcp1.4 CP_IRQ handling and SW
>> encryption tracking
>>
>> "hdcp_encrypted" flag is defined to denote the HDCP1.4 encryption status.
>> This SW tracking is used to determine the need for real hdcp1.4 disable and
>> hdcp_check_link upon CP_IRQ.
>>
>> On CP_IRQ we filter the CP_IRQ related to the states like Link failure and
>> reauthentication req etc and handle them in hdcp_check_link.
>> CP_IRQ corresponding to the authentication msg availability are ignored.
>>
>> WARN_ON is added for the abrupt stop of HDCP encryption of a port.
>>
>> v2:
>> bool is used in struct for the cleaner coding. [Daniel]
>> check_link work_fn is scheduled for cp_irq handling [Daniel]
>>
>> Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
>> ---
>> drivers/gpu/drm/i915/intel_dp.c | 2 +-
>> drivers/gpu/drm/i915/intel_drv.h | 5 ++- drivers/gpu/drm/i915/intel_hdcp.c |
>> 73 ++++++++++++++++++++++++++++-----------
>> 3 files changed, 58 insertions(+), 22 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>> index 815ee68efa2f..9ce05819fc11 100644
>> --- a/drivers/gpu/drm/i915/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/intel_dp.c
>> @@ -4776,7 +4776,7 @@ static void intel_dp_check_service_irq(struct intel_dp
>> *intel_dp)
>> intel_dp_handle_test_request(intel_dp);
>>
>> if (val & DP_CP_IRQ)
>> - intel_hdcp_check_link(intel_dp->attached_connector);
>> + intel_hdcp_handle_cp_irq(intel_dp->attached_connector);
>>
>> if (val & DP_SINK_SPECIFIC_IRQ)
>> DRM_DEBUG_DRIVER("Sink specific irq unhandled\n"); diff --git
>> a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>> index 63e009286d5f..13a41e8cf4ff 100644
>> --- a/drivers/gpu/drm/i915/intel_drv.h
>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>> @@ -399,6 +399,9 @@ struct intel_hdcp {
>> struct delayed_work check_work;
>> struct work_struct prop_work;
>>
>> + /* HDCP1.4 Encryption status */
>> + bool hdcp_encrypted;
>> +
>> /* HDCP2.2 related definitions */
>> /* Flag indicates whether this connector supports HDCP2.2 or not. */
>> bool hdcp2_supported;
>> @@ -2073,10 +2076,10 @@ int intel_hdcp_init(struct intel_connector
>> *connector,
>> bool hdcp2_supported);
>> int intel_hdcp_enable(struct intel_connector *connector); int
>> intel_hdcp_disable(struct intel_connector *connector); -int
>> intel_hdcp_check_link(struct intel_connector *connector); bool
>> is_hdcp_supported(struct drm_i915_private *dev_priv, enum port port); bool
>> intel_hdcp_capable(struct intel_connector *connector); bool
>> is_hdcp2_supported(struct drm_i915_private *dev_priv);
>> +void intel_hdcp_handle_cp_irq(struct intel_connector *connector);
>>
>> /* intel_psr.c */
>> #define CAN_PSR(dev_priv) (HAS_PSR(dev_priv) && dev_priv->psr.sink_support)
>> diff --git a/drivers/gpu/drm/i915/intel_hdcp.c
>> b/drivers/gpu/drm/i915/intel_hdcp.c
>> index e0bb5f32ba90..c1b057f1501b 100644
>> --- a/drivers/gpu/drm/i915/intel_hdcp.c
>> +++ b/drivers/gpu/drm/i915/intel_hdcp.c
>> @@ -74,6 +74,16 @@ bool intel_hdcp_capable(struct intel_connector
>> *connector)
>> return capable;
>> }
>>
>> +static inline bool intel_hdcp_in_use(struct intel_connector *connector)
>> +{
>> + struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
>> + enum port port = connector->encoder->port;
>> + u32 reg;
>> +
>> + reg = I915_READ(PORT_HDCP_STATUS(port));
>> + return reg & HDCP_STATUS_ENC;
>> +}
>> +
>> static int intel_hdcp_poll_ksv_fifo(struct intel_digital_port *intel_dig_port,
>> const struct intel_hdcp_shim *shim) { @@ -
>> 668,6 +678,7 @@ static int _intel_hdcp_disable(struct intel_connector
>> *connector)
>> DRM_DEBUG_KMS("[%s:%d] HDCP is being disabled...\n",
>> connector->base.name, connector->base.base.id);
>>
>> + hdcp->hdcp_encrypted = false;
>> I915_WRITE(PORT_HDCP_CONF(port), 0);
>> if (intel_wait_for_register(dev_priv, PORT_HDCP_STATUS(port), ~0, 0,
>> ENCRYPT_STATUS_CHANGE_TIMEOUT_MS)) {
>> @@ -713,8 +724,10 @@ static int _intel_hdcp_enable(struct intel_connector
>> *connector)
>> /* Incase of authentication failures, HDCP spec expects reauth. */
>> for (i = 0; i < tries; i++) {
>> ret = intel_hdcp_auth(conn_to_dig_port(connector), hdcp-
>>> shim);
>> - if (!ret)
>> + if (!ret) {
>> + hdcp->hdcp_encrypted = true;
>> return 0;
>> + }
>>
>> DRM_DEBUG_KMS("HDCP Auth failure (%d)\n", ret);
>>
>> @@ -741,16 +754,17 @@ int intel_hdcp_check_link(struct intel_connector
>> *connector)
>> enum port port = intel_dig_port->base.port;
>> int ret = 0;
>>
>> - if (!hdcp->shim)
>> - return -ENOENT;
>> -
>> mutex_lock(&hdcp->mutex);
>>
>> - if (hdcp->value == DRM_MODE_CONTENT_PROTECTION_UNDESIRED)
>> + /* Check_link valid only when HDCP1.4 is enabled */
>> + if (hdcp->value != DRM_MODE_CONTENT_PROTECTION_ENABLED ||
>> + !hdcp->hdcp_encrypted) {
>> + ret = -EINVAL;
>> goto out;
>> + }
>>
>> - if (!(I915_READ(PORT_HDCP_STATUS(port)) & HDCP_STATUS_ENC)) {
>> - DRM_ERROR("%s:%d HDCP check failed: link is not
>> encrypted,%x\n",
>> + if (WARN_ON(!intel_hdcp_in_use(connector))) {
>> + DRM_ERROR("%s:%d HDCP link stopped encryption,%x\n",
>> connector->base.name, connector->base.base.id,
>> I915_READ(PORT_HDCP_STATUS(port)));
>> ret = -ENXIO;
>> @@ -791,18 +805,6 @@ int intel_hdcp_check_link(struct intel_connector
>> *connector)
>> return ret;
>> }
>>
>> -static void intel_hdcp_check_work(struct work_struct *work) -{
>> - struct intel_hdcp *hdcp = container_of(to_delayed_work(work),
>> - struct intel_hdcp,
>> - check_work);
>> - struct intel_connector *connector = intel_hdcp_to_connector(hdcp);
>> -
>> - if (!intel_hdcp_check_link(connector))
>> - schedule_delayed_work(&hdcp->check_work,
>> - DRM_HDCP_CHECK_PERIOD_MS);
>> -}
>> -
>> static void intel_hdcp_prop_work(struct work_struct *work) {
>> struct intel_hdcp *hdcp = container_of(work, struct intel_hdcp, @@ -
>> 1120,6 +1122,18 @@ int hdcp2_deauthenticate_port(struct intel_connector
>> *connector)
>> return hdcp2_close_mei_session(connector);
>> }
>>
>> +static void intel_hdcp_check_work(struct work_struct *work) {
> Why this code movement for check_work. If not intentional no need for this change.
> With proper justification or this fixed.
All common(1.4 and 2.2) HDCP functions (enable, disable, check_work etc)
are gathered together
Thanks for R-b.

--Ram
>
> Reviewed-by: Uma Shankar <uma.shankar@intel.com>
>
>> + struct intel_hdcp *hdcp = container_of(to_delayed_work(work),
>> + struct intel_hdcp,
>> + check_work);
>> + struct intel_connector *connector = intel_hdcp_to_connector(hdcp);
>> +
>> + if (!intel_hdcp_check_link(connector))
>> + schedule_delayed_work(&hdcp->check_work,
>> + DRM_HDCP_CHECK_PERIOD_MS);
>> +}
>> +
>> static int i915_hdcp_component_bind(struct device *i915_kdev,
>> struct device *mei_kdev, void *data) { @@ -
>> 1288,7 +1302,8 @@ int intel_hdcp_disable(struct intel_connector *connector)
>>
>> if (hdcp->value != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
>> hdcp->value =
>> DRM_MODE_CONTENT_PROTECTION_UNDESIRED;
>> - ret = _intel_hdcp_disable(connector);
>> + if (hdcp->hdcp_encrypted)
>> + ret = _intel_hdcp_disable(connector);
>> }
>>
>> mutex_unlock(&hdcp->mutex);
>> @@ -1328,3 +1343,21 @@ void intel_hdcp_atomic_check(struct drm_connector
>> *connector,
>> new_state->crtc);
>> crtc_state->mode_changed = true;
>> }
>> +
>> +/* Handles the CP_IRQ raised from the DP HDCP sink */ void
>> +intel_hdcp_handle_cp_irq(struct intel_connector *connector) {
>> + struct intel_hdcp *hdcp = &connector->hdcp;
>> +
>> + if (!hdcp->shim)
>> + return;
>> +
>> + /*
>> + * CP_IRQ could be triggered due to 1. HDCP2.2 auth msgs availability,
>> + * 2. link failure and 3. repeater reauth request. At present we dont
>> + * handle the CP_IRQ for the HDCP2.2 auth msg availability for read.
>> + * To handle other two causes for CP_IRQ we have the work_fn which is
>> + * scheduled here.
>> + */
>> + schedule_delayed_work(&hdcp->check_work, 0); }
>> --
>> 2.7.4

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