Hi Tal, > > > mctp-i2c rx implementation doesn't call > > > __i2c_transfer which calls the i2c reply trace function. > > > > No, but we can trace the i2c rx path through the trace_i2c_slave > > tracepoint. It is a little messier than tracing trace_i2c_write, > > but > > has been sufficient with the debugging I've needed in the past. > > Oh, I missed that. > I had to test it with an older kernel without i2c_slave tracing > so I looked only at the regular i2c and mctp trace paths.
OK! That tracepoint was (coincidentally) added in 5.18, same as the MCTP-over-i2c transport. So we should have coverage for both features on upstream kernels, at least. > > > Add an mctp_reply trace function that will be used instead. > > > > Can you elaborate a little on what you were/are looking to inspect > > here? (mainly: which packet fields are you interested in?) That > > will > > help to determine the best approach here. > > Sure, I basically wanted to trace the i2c packet buffer in a simple > way. OK - did you specifically need the i2c transport headers? Since the MCTP interfaces are regular net devices, the easiest way to trace generic MCTP transfers is generally via a packet capture (tcpdump, wireshark, etc). Cheers, Jeremy
