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

Shankar, Uma
2019-02-04T14:09:48Z

>-----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.

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