actually I want change eth0 to eth1 & eth0 to eth1, normally fec initialize at first， I compile fec && smsc95xx as module to change the sequence . it is ok in imx8 4.19,but in imx6q 4.1.15 when I modprobe fec, causing smsc95xx reset , I couldn't change the eth0 eth1 sequence
thanks for your docment. I'll try KGDB . I have tried ftrace tools . It bothers me a lot ,because on our imx8mm board 4.19 kernel , it didn't happen , I can modprobe fec and won't influence the smsc95xx.
in general one can check if smsc95xx driver is built into the kernel ("=y") or built
as a module ("=m") or is not selected.