On 06/06/2019 17:44, Dmitry Osipenko wrote: > 06.06.2019 19:32, Jon Hunter пишет: >> >> On 06/06/2019 16:18, Dmitry Osipenko wrote: >> >> ... >> >>>>> If I understood everything correctly, the FIFO buffer is shared among >>>>> all of the ADMA clients and hence it should be up to the ADMA driver to >>>>> manage the quotas of the clients. So if there is only one client that >>>>> uses ADMA at a time, then this client will get a whole FIFO buffer, but >>>>> once another client starts to use ADMA, then the ADMA driver will have >>>>> to reconfigure hardware to split the quotas. >>>> >>>> The FIFO quotas are managed by the ADMAIF driver (does not exist in >>>> mainline currently but we are working to upstream this) because it is >>>> this device that owns and needs to configure the FIFOs. So it is really >>>> a means to pass the information from the ADMAIF to the ADMA. >>> >>> So you'd want to reserve a larger FIFO for an audio channel that has a >>> higher audio rate since it will perform reads more often. You could also >>> prioritize one channel over the others, like in a case of audio call for >>> example. >>> >>> Is the shared buffer smaller than may be needed by clients in a worst >>> case scenario? If you could split the quotas statically such that each >>> client won't ever starve, then seems there is no much need in the >>> dynamic configuration. >> >> Actually, this is still very much relevant for the static case. Even if >> we defined a static configuration of the FIFO mapping in the ADMAIF >> driver we still need to pass this information to the ADMA. I don't >> really like the idea of having it statically defined in two different >> drivers. > > Ah, so you need to apply the same configuration in two places. Correct? > > Are ADMAIF and ADMA really two different hardware blocks? Or you > artificially decoupled the ADMA driver? These are two different hardware modules with their own register sets. Yes otherwise, it would be a lot simpler! Jon -- nvpublic
