On 04/11/2016 11:27 AM, Jose Abreu wrote: > Hi Lars, > > > On 09-04-2016 16:02, Lars-Peter Clausen wrote: >> On 04/08/2016 06:12 PM, Jose Abreu wrote: >> [...] >>>> [...] >>>>> +- adi,enable-audio: If set the ADV7511 driver will register a codec interface >>>>> + into ALSA SoC. >>>> This is not a description of the hardware. >>> Is this okay: "adi,enable-audio: Set this boolean parameter if ADV7511 >>> transmitter routes audio signals" ? >> I don't think we need this property. There is no problem with registering >> the audio part unconditionally. As long as there is no connection we wont >> create a sound card that is exposed to userspace. >> > > This change was suggested by Laurent Pinchart and was introduced in v3. Quoting > Laurent: > "The idea is that enabling support for ADV7511 audio in the kernel isn't coupled > with whether the system includes audio support. It would be confusing, and would > also waste resources, to create a Linux sound device when no sound channel is > routed on the board." I wouldn't care too much about this at this point, the extra amount of resources required for registering the CODEC (but not the sound card) is just a few bytes (sizeof(struct snd_soc_codec)). Nevertheless what we should do is describe the hardware and from this information infer whether there is a audio connection or not and if there is none we might skip registering the CODEC. In my opinion this hardware description should be modeled using of-graph, having a connection between the SoC side and the adv7511 SPDIF or I2S port.
