Hi, I'm doing a study of kernel (4.19.16) configuration and I found something strange.I did research but could not find the answer. According the Kconfig file for DRM(https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/Kconfig#L26 ), CONFIG_DRM_MIPI_DSI depends on CONFIG_DRM. However, in my current Ubuntu config (4.18.0-15-generic) CONFIG_DRM_MIPI_DSI=y and CONFIG_DRM=m, it seems that these two items violate the dependency relationship. I looked up document for Kconfig (https://www.kernel.org/doc/Documentation/kbuild/kconfig-language.txt) but could not find such a case. Ideally, CONFIG_DRM_MIPI_DSI should be forced to configured to be a loadable module but this item is a boolean(no chance to be a loadable module) in the Kconfig. A step back approach is to make CONFIG_DRM to y but the kconfig system does not do this. Is it because this pattern is undefined in kconfig? git blame: https://github.com/torvalds/linux/commit/068a00233969833f1ba925e7627797489efd6041 Another similar case is CONFIG_MTD=m and CONFIG_LEDS_TRIGGER_MTD=y where CONFIG_LEDS_TRIGGER_MTD depends on CONFIG_MTD. git blame : https://github.com/torvalds/linux/blame/e60b5f79bd7529e76b13cf1e85823abbd0e33634/drivers/leds/trigger/Kconfig#L41 Hsuan-Chi Thanks