Re: [PATCH v10 08/40] drm/i915: Enable and Disable of HDCP2.2

Shankar, Uma
2019-02-04T14:17:18Z

>-----Original Message-----
>From: dri-devel [mailto:dri-devel-bounces@lists.freedesktop.org] On Behalf Of
>Ramalingam C
>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>
>Subject: [PATCH v10 08/40] drm/i915: Enable and Disable of HDCP2.2
>
>Considering that HDCP2.2 is more secure than HDCP1.4, When a setup supports
>HDCP2.2 and HDCP1.4, HDCP2.2 will be enabled.
>
>When HDCP2.2 enabling fails and HDCP1.4 is supported, HDCP1.4 is enabled.
>
>This change implements a sequence of enabling and disabling of
>HDCP2.2 authentication and HDCP2.2 port encryption.
>
>v2:
> Included few optimization suggestions [Chris Wilson]
> Commit message is updated as per the rebased version.
> intel_wait_for_register is used instead of wait_for. [Chris Wilson]
>v3:
> Extra comment added and Style issue fixed [Uma]
>v4:
> Rebased as part of patch reordering.
> HDCP2 encryption status is tracked.
> HW state check is moved into WARN_ON [Daniel]
>v5:
> Redefined the mei service functions as per comp redesign.
> Merged patches related to hdcp2.2 enabling and disabling [Sean Paul].
> Required shim functionality is defined [Sean Paul]
>v6:
> Return values are handles [Uma]
> Realigned the code.
> Check for comp_master is removed.
>v7:
> HDCP2.2 is attempted only if mei interface is up.
> Adjust to the new interface
> Avoid bool usage in struct [Tomas]
>v8:
> mei_binded status check is removed.
> %s/hdcp2_in_use/hdcp2_encrypted
>v9:
> bool is used in struct intel_hdcp. [Daniel]
>
>Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
>Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>---
> drivers/gpu/drm/i915/intel_drv.h | 7 ++
> drivers/gpu/drm/i915/intel_hdcp.c | 202
>+++++++++++++++++++++++++++++++++++---
> 2 files changed, 195 insertions(+), 14 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>index 13a41e8cf4ff..31c7a4577ca9 100644
>--- a/drivers/gpu/drm/i915/intel_drv.h
>+++ b/drivers/gpu/drm/i915/intel_drv.h
>@@ -389,6 +389,10 @@ struct intel_hdcp_shim {
>
> /* HDCP adaptation(DP/HDMI) required on the port */
> enum hdcp_wired_protocol protocol;
>+
>+ /* Detects whether Panel is HDCP2.2 capable */

Make Panel as Sink.

>+ int (*hdcp_2_2_capable)(struct intel_digital_port *intel_dig_port,
>+ bool *capable);
> };
>
> struct intel_hdcp {
>@@ -406,6 +410,9 @@ struct intel_hdcp {
> /* Flag indicates whether this connector supports HDCP2.2 or not. */
> bool hdcp2_supported;
>
>+ /* HDCP2.2 Encryption status */
>+ bool hdcp2_encrypted;
>+
> /*
> * Content Stream Type defined by content owner. TYPE0(0x0) content
>can
> * flow in the link protected by HDCP2.2 or HDCP1.4, where as
>TYPE1(0x1) diff --git a/drivers/gpu/drm/i915/intel_hdcp.c
>b/drivers/gpu/drm/i915/intel_hdcp.c
>index c1b057f1501b..fbf8b7893bfa 100644
>--- a/drivers/gpu/drm/i915/intel_hdcp.c
>+++ b/drivers/gpu/drm/i915/intel_hdcp.c
>@@ -74,6 +74,23 @@ bool intel_hdcp_capable(struct intel_connector
>*connector)
> return capable;
> }
>
>+/* Is HDCP2.2 capable on Platform and Sink */ static bool
>+intel_hdcp2_capable(struct intel_connector *connector) {
>+ struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
>+ struct intel_hdcp *hdcp = &connector->hdcp;
>+ bool capable = false;
>+
>+ /* I915 support for HDCP2.2 */
>+ if (!hdcp->hdcp2_supported)
>+ return false;
>+
>+ /* Sink's capability for HDCP2.2 */
>+ hdcp->shim->hdcp_2_2_capable(intel_dig_port, &capable);
>+
>+ return capable;
>+}
>+
> static inline bool intel_hdcp_in_use(struct intel_connector *connector) {
> struct drm_i915_private *dev_priv = to_i915(connector->base.dev); @@
>-1094,8 +1111,7 @@ int hdcp2_authenticate_port(struct intel_connector
>*connector)
> return ret;
> }
>
>-static __attribute__((unused))
>-int hdcp2_close_mei_session(struct intel_connector *connector)
>+static int hdcp2_close_mei_session(struct intel_connector *connector)
> {
> struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
> struct i915_hdcp_comp_master *comp;
>@@ -1116,12 +1132,157 @@ int hdcp2_close_mei_session(struct
>intel_connector *connector)
> return ret;
> }
>
>-static __attribute__((unused))
>-int hdcp2_deauthenticate_port(struct intel_connector *connector)
>+static int hdcp2_deauthenticate_port(struct intel_connector *connector)
> {
> return hdcp2_close_mei_session(connector);
> }
>
>+static int hdcp2_authenticate_sink(struct intel_connector *connector) {
>+ DRM_ERROR("Sink authentication is done in subsequent patches\n");
>+
>+ return -EINVAL;
>+}
>+
>+static int hdcp2_enable_encryption(struct intel_connector *connector) {
>+ struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
>+ struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
>+ struct intel_hdcp *hdcp = &connector->hdcp;
>+ enum port port = connector->encoder->port;
>+ int ret;
>+
>+ WARN_ON(I915_READ(HDCP2_STATUS_DDI(port)) &
>LINK_ENCRYPTION_STATUS);
>+
>+ if (hdcp->shim->toggle_signalling) {
>+ ret = hdcp->shim->toggle_signalling(intel_dig_port, true);
>+ if (ret) {
>+ DRM_ERROR("Failed to enable HDCP signalling. %d\n",
>+ ret);
>+ return ret;
>+ }
>+ }
>+
>+ if (I915_READ(HDCP2_STATUS_DDI(port)) & LINK_AUTH_STATUS) {
>+ /* Link is Authenticated. Now set for Encryption */
>+ I915_WRITE(HDCP2_CTL_DDI(port),
>+ I915_READ(HDCP2_CTL_DDI(port)) |
>+ CTL_LINK_ENCRYPTION_REQ);
>+ }
>+
>+ ret = intel_wait_for_register(dev_priv, HDCP2_STATUS_DDI(port),
>+ LINK_ENCRYPTION_STATUS,
>+ LINK_ENCRYPTION_STATUS,
>+ ENCRYPT_STATUS_CHANGE_TIMEOUT_MS);
>+
>+ return ret;
>+}
>+
>+static int hdcp2_disable_encryption(struct intel_connector *connector)
>+{
>+ struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
>+ struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
>+ struct intel_hdcp *hdcp = &connector->hdcp;
>+ enum port port = connector->encoder->port;
>+ int ret;
>+
>+ WARN_ON(!(I915_READ(HDCP2_STATUS_DDI(port)) &
>+LINK_ENCRYPTION_STATUS));
>+
>+ I915_WRITE(HDCP2_CTL_DDI(port),
>+ I915_READ(HDCP2_CTL_DDI(port)) &
>~CTL_LINK_ENCRYPTION_REQ);
>+
>+ ret = intel_wait_for_register(dev_priv, HDCP2_STATUS_DDI(port),
>+ LINK_ENCRYPTION_STATUS, 0x0,
>+ ENCRYPT_STATUS_CHANGE_TIMEOUT_MS);
>+ if (ret == -ETIMEDOUT)
>+ DRM_DEBUG_KMS("Disable Encryption Timedout");
>+
>+ if (hdcp->shim->toggle_signalling) {
>+ ret = hdcp->shim->toggle_signalling(intel_dig_port, false);
>+ if (ret) {
>+ DRM_ERROR("Failed to disable HDCP signalling. %d\n",
>+ ret);
>+ return ret;
>+ }
>+ }
>+
>+ return ret;
>+}
>+
>+static int hdcp2_authenticate_and_encrypt(struct intel_connector
>+*connector) {
>+ int ret, i, tries = 3;
>+
>+ for (i = 0; i < tries; i++) {
>+ ret = hdcp2_authenticate_sink(connector);
>+ if (!ret)
>+ break;
>+
>+ /* Clearing the mei hdcp session */
>+ DRM_DEBUG_KMS("HDCP2.2 Auth %d of %d Failed.(%d)\n",
>+ i + 1, tries, ret);
>+ if (hdcp2_deauthenticate_port(connector) < 0)
>+ DRM_DEBUG_KMS("Port deauth failed.\n");
>+ }
>+
>+ if (i != tries) {
>+ /*
>+ * Ensuring the required 200mSec min time interval between
>+ * Session Key Exchange and encryption.
>+ */
>+ msleep(HDCP_2_2_DELAY_BEFORE_ENCRYPTION_EN);
>+ ret = hdcp2_enable_encryption(connector);
>+ if (ret < 0) {
>+ DRM_DEBUG_KMS("Encryption Enable Failed.(%d)\n",
>ret);
>+ if (hdcp2_deauthenticate_port(connector) < 0)
>+ DRM_DEBUG_KMS("Port deauth failed.\n");
>+ }
>+ }
>+
>+ return ret;
>+}
>+
>+static int _intel_hdcp2_enable(struct intel_connector *connector) {
>+ struct intel_hdcp *hdcp = &connector->hdcp;
>+ int ret;
>+
>+ DRM_DEBUG_KMS("[%s:%d] HDCP2.2 is being enabled. Type: %d\n",
>+ connector->base.name, connector->base.base.id,
>+ hdcp->content_type);
>+
>+ ret = hdcp2_authenticate_and_encrypt(connector);
>+ if (ret) {
>+ DRM_DEBUG_KMS("HDCP2 Type%d Enabling Failed. (%d)\n",
>+ hdcp->content_type, ret);
>+ return ret;
>+ }
>+
>+ DRM_DEBUG_KMS("[%s:%d] HDCP2.2 is enabled. Type %d\n",
>+ connector->base.name, connector->base.base.id,
>+ hdcp->content_type);
>+
>+ hdcp->hdcp2_encrypted = true;
>+ return 0;
>+}
>+
>+static int _intel_hdcp2_disable(struct intel_connector *connector) {
>+ int ret;
>+
>+ DRM_DEBUG_KMS("[%s:%d] HDCP2.2 is being Disabled\n",
>+ connector->base.name, connector->base.base.id);
>+
>+ ret = hdcp2_disable_encryption(connector);
>+
>+ if (hdcp2_deauthenticate_port(connector) < 0)
>+ DRM_DEBUG_KMS("Port deauth failed.\n");
>+
>+ connector->hdcp.hdcp2_encrypted = false;
>+
>+ return ret;
>+}
>+
> static void intel_hdcp_check_work(struct work_struct *work) {
> struct intel_hdcp *hdcp = container_of(to_delayed_work(work),
>@@ -1270,22 +1431,33 @@ int intel_hdcp_init(struct intel_connector
>*connector, int intel_hdcp_enable(struct intel_connector *connector) {
> struct intel_hdcp *hdcp = &connector->hdcp;
>- int ret;
>+ int ret = -EINVAL;
>
> if (!hdcp->shim)
> return -ENOENT;
>
> mutex_lock(&hdcp->mutex);
>
>- ret = _intel_hdcp_enable(connector);
>- if (ret)
>- goto out;
>+ /*
>+ * 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))
>+ ret = _intel_hdcp2_enable(connector);
>+
>+ /* When HDCP2.2 fails, HDCP1.4 will be attempted */
>+ if (ret && intel_hdcp_capable(connector)) {
>+ ret = _intel_hdcp_enable(connector);
>+ if (!ret)
>+ schedule_delayed_work(&hdcp->check_work,
>+ DRM_HDCP_CHECK_PERIOD_MS);
>+ }
>+
>+ if (!ret) {
>+ hdcp->value = DRM_MODE_CONTENT_PROTECTION_ENABLED;
>+ schedule_work(&hdcp->prop_work);

Looks like check_work is not called for 2.2. Fix this.

With this fixed.
Reviewed-by: Uma Shankar <uma.shankar@intel.com>

>+ }
>
>- hdcp->value = DRM_MODE_CONTENT_PROTECTION_ENABLED;
>- schedule_work(&hdcp->prop_work);
>- schedule_delayed_work(&hdcp->check_work,
>- DRM_HDCP_CHECK_PERIOD_MS);
>-out:
> mutex_unlock(&hdcp->mutex);
> return ret;
> }
>@@ -1302,7 +1474,9 @@ int intel_hdcp_disable(struct intel_connector
>*connector)
>
> if (hdcp->value != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
> hdcp->value =
>DRM_MODE_CONTENT_PROTECTION_UNDESIRED;
>- if (hdcp->hdcp_encrypted)
>+ if (hdcp->hdcp2_encrypted)
>+ ret = _intel_hdcp2_disable(connector);
>+ else if (hdcp->hdcp_encrypted)
> ret = _intel_hdcp_disable(connector);
> }
>
>--
>2.7.4
>
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