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. DRM_TTM_HELPER and DRM_GEM_DMA_HELPER look like they have the same problem in theory even if there is no possible configuration that shows it. For consistency, do the same change to those. Closes: https://lore.kernel.org/all/20250121-greedy-flounder-of-abundance-4d2ee8-mkl@xxxxxxxxxxxxxx Reported-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Tested-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- drivers/gpu/drm/Kconfig | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index 0fe99d440bfa..805c6c78498f 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -293,6 +293,7 @@ config DRM_TTM_HELPER tristate depends on DRM select DRM_TTM + select DRM_KMS_HELPER if DRM_FBDEV_EMULATION select FB_CORE if DRM_FBDEV_EMULATION select FB_SYSMEM_HELPERS_DEFERRED if DRM_FBDEV_EMULATION help @@ -301,6 +302,7 @@ config DRM_TTM_HELPER config DRM_GEM_DMA_HELPER tristate depends on DRM + select DRM_KMS_HELPER if DRM_FBDEV_EMULATION select FB_CORE if DRM_FBDEV_EMULATION select FB_DMAMEM_HELPERS_DEFERRED if DRM_FBDEV_EMULATION help @@ -309,6 +311,7 @@ config DRM_GEM_DMA_HELPER config DRM_GEM_SHMEM_HELPER tristate depends on DRM && MMU + select DRM_KMS_HELPER if DRM_FBDEV_EMULATION select FB_CORE if DRM_FBDEV_EMULATION select FB_SYSMEM_HELPERS_DEFERRED if DRM_FBDEV_EMULATION help -- 2.39.5
