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. Jon -- nvpublic
