diff --git a/Documentation/DocBook/media/dvb/frontend.xml b/Documentation/DocBook/media/dvb/frontend.xml index b1f01239d4da..086e62bcad11 100644 --- a/Documentation/DocBook/media/dvb/frontend.xml +++ b/Documentation/DocBook/media/dvb/frontend.xml @@ -221,8 +221,20 @@ by
frontend parameters The kind of parameters passed to the frontend device for tuning depend on -the kind of hardware you are using. All kinds of parameters are combined as an -union in the FrontendParameters structure: +the kind of hardware you are using. +The struct dvb_frontend_parameters uses an +union with specific per-system parameters. However, as newer delivery systems +required more data, the structure size weren't enough to fit, and just +extending its size would break the existing applications. So, those parameters +were replaced by the usage of +FE_GET_PROPERTY/FE_SET_PROPERTY ioctl's. The +new API is flexible enough to add new parameters to existing delivery systems, +and to add newer delivery systems. +So, newer applications should use +FE_GET_PROPERTY/FE_SET_PROPERTY instead, in +order to be able to support the newer System Delivery like DVB-S2, DVB-T2, +DVB-C2, ISDB, etc. +All kinds of parameters are combined as an union in the FrontendParameters structure: struct dvb_frontend_parameters { uint32_t frequency; /⋆ (absolute) frequency in Hz for QAM/OFDM ⋆/