On 2022/02/22 Tue 16:50, liuqi (BA) wrote:
+CONFIG_CORESIGHT=y +CONFIG_CORESIGHT_LINKS_AND_SINKS=y +CONFIG_CORESIGHT_SOURCE_ETM4X=y
Why not =m for these three?
because ultrasoc driver depend on CONFIG_CORESIGHT_LINKS_AND_SINKS, and CONFIG_CORESIGHT_LINKS_AND_SINKS depend on CONFIG_CORESIGHT, I'm afraid that setting them as m may influence the load of driver.
I assume the UltraSoC driver you mentioned is also a kernel module.
If the UltraSoC driver uses symbols provided by CoreSight modules, dependency information will be generated automatically by depmod. And that dependency info will be used when loading modules.
If UltraSoC doesn't use symbols from CoreSight code, but do have runtime dependency on the CoreSight module, then a conf file should be installed under /etc/modprobe.d or /lib/modprobe.d. In that file using the "install" command to make sure CoreSight modules are loaded before UltraSoC. Please check `man 5 modprobe.d` for detail.
Regards, Kai