Due to the fact that writeback connectors behave in a special way in DRM (they always report being disconnected) we might confuse some userspace. Add a client capability for writeback connectors that will filter them out for clients that don't understand the capability.
Changelog: - only accept the capability if the client has already set the DRM_CLIENT_CAP_ATOMIC one.
Cc: Sean Paul seanpaul@chromium.org Cc: Brian Starkey brian.starkey@arm.com Signed-off-by: Liviu Dudau liviu.dudau@arm.com --- drivers/gpu/drm/drm_ioctl.c | 7 +++++++ drivers/gpu/drm/drm_mode_config.c | 5 +++++ include/drm/drm_file.h | 7 +++++++ include/uapi/drm/drm.h | 9 +++++++++ 4 files changed, 28 insertions(+)
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index 0d4cfb232576f..fe49fb0356b5a 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -334,6 +334,13 @@ drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv) return -EINVAL; file_priv->aspect_ratio_allowed = req->value; break; + case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS: + if (!file_priv->atomic) + return -EINVAL; + if (req->value > 1) + return -EINVAL; + file_priv->writeback_connectors = req->value; + break; default: return -EINVAL; } diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c index e5c653357024d..21e353bd3948e 100644 --- a/drivers/gpu/drm/drm_mode_config.c +++ b/drivers/gpu/drm/drm_mode_config.c @@ -145,6 +145,11 @@ int drm_mode_getresources(struct drm_device *dev, void *data, count = 0; connector_id = u64_to_user_ptr(card_res->connector_id_ptr); drm_for_each_connector_iter(connector, &conn_iter) { + /* only expose writeback connectors if userspace understands them */ + if (!file_priv->writeback_connectors && + (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK)) + continue; + if (drm_lease_held(file_priv, connector->base.id)) { if (count < card_res->count_connectors && put_user(connector->base.id, connector_id + count)) { diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h index 027ac16da3d15..26485acc51d79 100644 --- a/include/drm/drm_file.h +++ b/include/drm/drm_file.h @@ -192,6 +192,13 @@ struct drm_file { */ unsigned aspect_ratio_allowed:1;
+ /** + * @writeback_connectors: + * + * True if client understands writeback connectors + */ + unsigned writeback_connectors:1; + /** * @is_master: * diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h index 9c660e1688abe..300f336633f28 100644 --- a/include/uapi/drm/drm.h +++ b/include/uapi/drm/drm.h @@ -687,6 +687,15 @@ struct drm_get_cap { */ #define DRM_CLIENT_CAP_ASPECT_RATIO 4
+/** + * DRM_CLIENT_CAP_WRITEBACK_CONNECTORS + * + * If set to 1, the DRM core will expose special connectors to be used for + * writing back to memory the scene setup in the commit. Depends on client + * also supporting DRM_CLIENT_CAP_ATOMIC + */ +#define DRM_CLIENT_CAP_WRITEBACK_CONNECTORS 5 + /** DRM_IOCTL_SET_CLIENT_CAP ioctl argument type */ struct drm_set_client_cap { __u64 capability;