I'm trying to test minimum timing and performance using peripheral and central ISO under Zephyr.
I'm trying to play with the interval and latency values under the central sample app.
If I use anything under 5 msec (5U * USEC_PER_MSEC) for interval_us under central_iso I'm getting the following messages (I changed debug to warning messages so I can see the error):
[00:00:00.004,760] <wrn> bt_iso: id 0, latency C to P 5, latency P to C 5, interval C to P 255, interval P to C 255, sca 0, packing 0, framing 0, num_cis 1
[00:00:00.004,760] <wrn> bt_iso: [0]: id 0, c_phy 2, c_sdu 251, c_rtn 1, p_phy 2, p_sdu 0, p_rtn 0
[00:00:00.004,791] <wrn> bt_hci_core: buf 0x20009654 opcode 0x2062 len 27
[00:00:00.005,004] <wrn> bt_hci_core: opcode 0x2062 status 0x11
[00:00:00.005,035] <wrn> bt_iso: Unexpected response to hci_le_set_cig_params
Failed to create CIG (-5)
When I look at bt_iso_cig_create I see that it calls valid_cig_param which in turn checks minimum interval for 255 usec
HCI status 0x11 means Unsupported Feature or Parameter Value.
What are the correct boundaries and what reason is there for valid_cig_param to check values the controller doesn't accept?
Thanks,
Guy.
