From: Arnd Bergmann <arnd@xxxxxxxx> In the combination of DRM_KMS_HELPER=m, DRM_GEM_SHMEM_HELPER=y, DRM_FBDEV_EMULATION=y, The shmem code fails to link against the KMS helpers: x86_64-linux-ld: vmlinux.o: in function `drm_fbdev_shmem_driver_fbdev_probe': (.text+0xeec601): undefined reference to `drm_fb_helper_alloc_info' x86_64-linux-ld: (.text+0xeec633): undefined reference to `drm_fb_helper_fill_info' x86_64-linux-ld: vmlinux.o: in function `drm_fbdev_shmem_get_page': drm_fbdev_shmem.c:(.text+0xeec7d2): undefined reference to `drm_gem_fb_get_obj' x86_64-linux-ld: vmlinux.o: in function `drm_fbdev_shmem_fb_mmap': drm_fbdev_shmem.c:(.text+0xeec9f6): undefined reference to `drm_gem_fb_get_obj' x86_64-linux-ld: vmlinux.o: in function `drm_fbdev_shmem_defio_imageblit': (.rodata+0x5b2288): undefined reference to `drm_fb_helper_check_var' x86_64-linux-ld: (.rodata+0x5b2290): undefined reference to `drm_fb_helper_set_par' This can happen for a number of device drivers that select DRM_GEM_SHMEM_HELPER without also selecting DRM_KMS_HELPER. To work around this, add another select that forces DRM_KMS_HELPER to be built-in rather than a loadable module, but only if FBDEV emulation is also enabled. Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- drivers/gpu/drm/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index 0fe99d440bfa..a8d2dffbc82f 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -311,6 +311,7 @@ config DRM_GEM_SHMEM_HELPER depends on DRM && MMU select FB_CORE if DRM_FBDEV_EMULATION select FB_SYSMEM_HELPERS_DEFERRED if DRM_FBDEV_EMULATION + select DRM_KMS_HELPER if DRM_FBDEV_EMULATION help Choose this if you need the GEM shmem helper functions -- 2.39.5