I am a newer of driver development. I have configured my linux kernel according to the Linux Device Driver chaper 4, enabled a lot of debug configuration. When I try to test a driver written by me, the kernel issues an oops. This oops, however, immediately flushed by chunks of other debug information. So, where could I find out the oops info which occurred in a flash.
By the way, can anyone explain the meaning of debug information below?
[ 1698.129712] evbug: Event. Dev: input0, Type: 0, Code: 0, Value: 0
This type of message flushed by screen and I even can't stop them.
To avoid a lot of useless information (in your case) you have to enable only and only what you really need to debug your module. I highly recommend to disable everything you enabled back. Then case-by-case you may enable debug features.
Next, there is a nice framework in kernel called Dynamic Debug. It allows at runtime enable or disable certain debug messages (be sure you have CONFIG_DYNAMIC_DEBUG=y in the Linux kernel configuration). More detailed description is available in Documentation/dynamic-debug-howto.txt.
evbug is a module to monitor input events in the kernel. There is one of the message it can issue. It's very simple one you may check at drivers/input/evbug.c. Unfortunately, it uses printk() calls directly and you can't manipulate its output through dynamic debug.
At the end the answer to your topic question is check output of dmesg command. But be aware that the kernel buffer for output is small enough and if you have a lot of logs you may miss some of them.