From: Arnd Bergmann Date: Mon, 29 Aug 2016 12:34:07 +0000 (+0200) Subject: drm/fb-helper: don't call remove_conflicting_framebuffers for FB=m && DRM=y X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=749cc6f7ed509e1be04e9c26d9cdc3c1f0dd13b4;p=openwrt%2Fstaging%2Fblogic.git drm/fb-helper: don't call remove_conflicting_framebuffers for FB=m && DRM=y When CONFIG_DRM_KMS_FB_HELPER is disabled, we can have a configuration in which some DRM drivers are built-in, but the framebuffer core is a loadable module. This results in a link error, such as: drivers/gpu/drm/radeon/radeon.o: In function `radeon_pci_probe': radeon_kfd.c:(.text.radeon_pci_probe+0xbc): undefined reference to `remove_conflicting_framebuffers' drivers/gpu/drm/amd/amdgpu/amdgpu.o: In function `amdgpu_pci_probe': amdgpu_mn.c:(.text.amdgpu_pci_probe+0xa8): undefined reference to `remove_conflicting_framebuffers' drivers/gpu/drm/mgag200/mgag200.o: In function `mga_vram_init': mgag200_ttm.c:(.text.mga_vram_init+0xa8): undefined reference to `remove_conflicting_framebuffers' drivers/gpu/drm/mgag200/mgag200.o: In function `mga_pci_probe': mgag200_ttm.c:(.text.mga_pci_probe+0x88): undefined reference to `remove_conflicting_framebuffers' Makefile:969: recipe for target 'vmlinux' failed This changes the compile-time check to IS_REACHABLE, which means we end up not calling remove_conflicting_framebuffers() in the configuration, which seems good enough, as we know that no framebuffer driver is loaded by the time that the built-in DRM driver calls remove_conflicting_framebuffers. We could alternatively avoid the link error by forcing CONFIG_FB to not be a module in this case, but that wouldn't change anything at runtime, and just make the already convoluted set of dependencies worse here. I could not find out what happens if the fbdev driver gets loaded as a module after the DRM driver is already initialized, but that is a case that can happen with or without this patch. Signed-off-by: Arnd Bergmann Fixes: 0a3bfe29f816 ("drm/fb-helper: Fix the dummy remove_conflicting_framebuffers") Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20160829123428.3260105-1-arnd@arndb.de Link: http://patchwork.freedesktop.org/patch/msgid/1472461923-14364-1-git-send-email-gnuiyl@gmail.com --- diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h index edc6cfd3aa34..797fb5f80c45 100644 --- a/include/drm/drm_fb_helper.h +++ b/include/drm/drm_fb_helper.h @@ -491,7 +491,7 @@ static inline int drm_fb_helper_remove_conflicting_framebuffers(struct apertures_struct *a, const char *name, bool primary) { -#if IS_ENABLED(CONFIG_FB) +#if IS_REACHABLE(CONFIG_FB) return remove_conflicting_framebuffers(a, name, primary); #else return 0;