[Intel-gfx] [PATCH v7 07/11] drm: Add Content protection type property
Pekka Paalanen
ppaalanen at gmail.com
Thu Jul 4 11:11:59 UTC 2019
On Tue, 7 May 2019 21:57:41 +0530
Ramalingam C <ramalingam.c at intel.com> wrote:
> This patch adds a DRM ENUM property to the selected connectors.
> This property is used for mentioning the protected content's type
> from userspace to kernel HDCP authentication.
>
> Type of the stream is decided by the protected content providers.
> Type 0 content can be rendered on any HDCP protected display wires.
> But Type 1 content can be rendered only on HDCP2.2 protected paths.
>
> So when a userspace sets this property to Type 1 and starts the HDCP
> enable, kernel will honour it only if HDCP2.2 authentication is through
> for type 1. Else HDCP enable will be failed.
>
> Need ACK for this new conenctor property from userspace consumer.
>
> v2:
> cp_content_type is replaced with content_protection_type [daniel]
> check at atomic_set_property is removed [Maarten]
> v3:
> %s/content_protection_type/hdcp_content_type [Pekka]
> v4:
> property is created for the first requested connector and then reused.
> [Danvet]
> v5:
> kernel doc nits addressed [Daniel]
> Rebased as part of patch reordering.
>
> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
> drivers/gpu/drm/drm_atomic_uapi.c | 4 ++++
> drivers/gpu/drm/drm_connector.c | 18 ++++++++++++++++
> drivers/gpu/drm/drm_hdcp.c | 36 ++++++++++++++++++++++++++++++-
> drivers/gpu/drm/i915/intel_hdcp.c | 4 +++-
> include/drm/drm_connector.h | 7 ++++++
> include/drm/drm_hdcp.h | 2 +-
> include/drm/drm_mode_config.h | 6 ++++++
> include/uapi/drm/drm_mode.h | 4 ++++
> 8 files changed, 78 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
> index 4131e669785a..a85f3ccfe699 100644
> --- a/drivers/gpu/drm/drm_atomic_uapi.c
> +++ b/drivers/gpu/drm/drm_atomic_uapi.c
> @@ -738,6 +738,8 @@ static int drm_atomic_connector_set_property(struct drm_connector *connector,
> return -EINVAL;
> }
> state->content_protection = val;
> + } else if (property == config->hdcp_content_type_property) {
> + state->hdcp_content_type = val;
> } else if (property == connector->colorspace_property) {
> state->colorspace = val;
> } else if (property == config->writeback_fb_id_property) {
> @@ -816,6 +818,8 @@ drm_atomic_connector_get_property(struct drm_connector *connector,
> *val = state->scaling_mode;
> } else if (property == config->content_protection_property) {
> *val = state->content_protection;
> + } else if (property == config->hdcp_content_type_property) {
> + *val = state->hdcp_content_type;
> } else if (property == config->writeback_fb_id_property) {
> /* Writeback framebuffer is one-shot, write and forget */
> *val = 0;
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index 764c7903edf6..de9e06583e8c 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
Hi,
below I have some comments and questions before I can say whether
https://gitlab.freedesktop.org/wayland/weston/merge_requests/48
adheres to this specification.
> @@ -955,6 +955,24 @@ static const struct drm_prop_enum_list hdmi_colorspaces[] = {
> * the value transitions from ENABLED to DESIRED. This signifies the link
> * is no longer protected and userspace should take appropriate action
> * (whatever that might be).
> + * HDCP Content Type:
> + * This property is used by the userspace to configure the kernel with
> + * to be displayed stream's content type. Content Type of a stream is
> + * decided by the owner of the stream, as HDCP Type0 or HDCP Type1.
> + *
> + * The value of the property can be one the below:
> + * - DRM_MODE_HDCP_CONTENT_TYPE0 = 0
If this doc is meant as the UAPI doc, it needs to use the string names
for enum property values, not the C language definitions (integers).
> + * HDCP Type0 streams can be transmitted on a link which is
> + * encrypted with HDCP 1.4 or HDCP 2.2.
This wording forbids using any future HDCP version for type0.
> + * - DRM_MODE_HDCP_CONTENT_TYPE1 = 1
> + * HDCP Type1 streams can be transmitted on a link which is
> + * encrypted only with HDCP 2.2.
This wording forbids using any future HDCP version for type1.
> + *
> + * Note that the HDCP Content Type property is specific to HDCP 2.2, and
> + * defaults to type 0. It is only exposed by drivers supporting HDCP 2.2
Not possible with a future HDCP version greater than 2.2?
Is it intended to be possible to add more content types in the future?
> + * If content type is changed when content_protection is not UNDESIRED,
> + * then kernel will disable the HDCP and re-enable with new type in the
> + * same atomic commit
Ok, very good to mention this.
> *
> * max bpc:
> * This range property is used by userspace to limit the bit depth. When
> diff --git a/drivers/gpu/drm/drm_hdcp.c b/drivers/gpu/drm/drm_hdcp.c
> index 0da7b3718bad..75402463466b 100644
> --- a/drivers/gpu/drm/drm_hdcp.c
> +++ b/drivers/gpu/drm/drm_hdcp.c
> @@ -342,23 +342,41 @@ static struct drm_prop_enum_list drm_cp_enum_list[] = {
> };
> DRM_ENUM_NAME_FN(drm_get_content_protection_name, drm_cp_enum_list)
>
> +static struct drm_prop_enum_list drm_hdcp_content_type_enum_list[] = {
> + { DRM_MODE_HDCP_CONTENT_TYPE0, "HDCP Type0" },
> + { DRM_MODE_HDCP_CONTENT_TYPE1, "HDCP Type1" },
> +};
> +DRM_ENUM_NAME_FN(drm_get_hdcp_content_type_name,
> + drm_hdcp_content_type_enum_list)
> +
> /**
> * drm_connector_attach_content_protection_property - attach content protection
> * property
> *
> * @connector: connector to attach CP property on.
> + * @hdcp_content_type: is HDCP Content Type property needed for connector
> *
> * This is used to add support for content protection on select connectors.
> * Content Protection is intentionally vague to allow for different underlying
> * technologies, however it is most implemented by HDCP.
> *
> + * When hdcp_content_type is true enum property called HDCP Content Type is
> + * created (if it is not already) and attached to the connector.
> + *
> + * This property is used for sending the protected content's stream type
> + * from userspace to kernel on selected connectors. Protected content provider
> + * will decide their type of their content and declare the same to kernel.
> + *
> + * Content type will be used during the HDCP 2.2 authentication.
> + * Content type will be set to &drm_connector_state.hdcp_content_type.
> + *
> * The content protection will be set to &drm_connector_state.content_protection
> *
> * Returns:
> * Zero on success, negative errno on failure.
> */
> int drm_connector_attach_content_protection_property(
> - struct drm_connector *connector)
> + struct drm_connector *connector, bool hdcp_content_type)
> {
> struct drm_device *dev = connector->dev;
> struct drm_property *prop =
> @@ -375,6 +393,22 @@ int drm_connector_attach_content_protection_property(
> DRM_MODE_CONTENT_PROTECTION_UNDESIRED);
> dev->mode_config.content_protection_property = prop;
>
> + if (!hdcp_content_type)
> + return 0;
> +
> + prop = dev->mode_config.hdcp_content_type_property;
> + if (!prop)
> + prop = drm_property_create_enum(dev, 0, "HDCP Content Type",
> + drm_hdcp_content_type_enum_list,
> + ARRAY_SIZE(
> + drm_hdcp_content_type_enum_list));
> + if (!prop)
> + return -ENOMEM;
> +
> + drm_object_attach_property(&connector->base, prop,
> + DRM_MODE_HDCP_CONTENT_TYPE0);
> + dev->mode_config.hdcp_content_type_property = prop;
> +
> return 0;
> }
> EXPORT_SYMBOL(drm_connector_attach_content_protection_property);
...
> diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
> index 83cd1636b9be..8ac03351fdee 100644
> --- a/include/uapi/drm/drm_mode.h
> +++ b/include/uapi/drm/drm_mode.h
> @@ -209,6 +209,10 @@ extern "C" {
> #define DRM_MODE_CONTENT_PROTECTION_DESIRED 1
> #define DRM_MODE_CONTENT_PROTECTION_ENABLED 2
>
> +/* Content Type classification for HDCP2.2 vs others */
> +#define DRM_MODE_HDCP_CONTENT_TYPE0 0
> +#define DRM_MODE_HDCP_CONTENT_TYPE1 1
These should not be in a UAPI header. The C language definitions must
never be exposed to userspace, or misguided userspace will start using
them.
Instead, UAPI uses the string names to discover the integers at runtime.
***
Questions about the already existing "Content Protection" property:
- What happens if userspace attempts to write "Enabled" into it?
- Where is the UAPI documentation that explains how userspace should be
using the property? (e.g. telling that you cannot set it to "Enabled")
Thanks,
pq
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