This is a note to let you know that I've just added the patch titled fbdev: simplefb: fix Kconfig dependencies to the 5.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: fbdev-simplefb-fix-kconfig-dependencies.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From ec7cc3f74b4236860ce612656aa5be7936d1c594 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann <arnd@xxxxxxxx> Date: Tue, 28 Sep 2021 16:52:10 +0200 Subject: fbdev: simplefb: fix Kconfig dependencies From: Arnd Bergmann <arnd@xxxxxxxx> commit ec7cc3f74b4236860ce612656aa5be7936d1c594 upstream. Configurations with both CONFIG_FB_SIMPLE=y and CONFIG_DRM_SIMPLEDRM=m are allowed by Kconfig because the 'depends on !DRM_SIMPLEDRM' dependency does not disallow FB_SIMPLE as long as SIMPLEDRM is not built-in. This can however result in a build failure when cfb_fillrect() etc are then also in loadable modules: x86_64-linux-ld: drivers/video/fbdev/simplefb.o:(.rodata+0x1f8): undefined reference to `cfb_fillrect' x86_64-linux-ld: drivers/video/fbdev/simplefb.o:(.rodata+0x200): undefined reference to `cfb_copyarea' x86_64-linux-ld: drivers/video/fbdev/simplefb.o:(.rodata+0x208): undefined reference to `cfb_imageblit' To work around this, change FB_SIMPLE to be a 'tristate' symbol, which still allows both to be =m together, but not one of them to be =y if the other one is =m. If a distro kernel picks this configuration, it can be determined by local policy which of the two modules gets loaded. The 'of_chosen' export is needed as this is the first loadable module referencing it. Alternatively, the Kconfig dependency could be changed to 'depends on DRM_SIMPLEDRM=n', which would forbid the configuration with both drivers. Fixes: 11e8f5fd223b ("drm: Add simpledrm driver") Acked-by: Rob Herring <robh@xxxxxxxxxx> # for drivers/of/ Link: https://lore.kernel.org/all/20210721151839.2484245-1-arnd@xxxxxxxxxx/ Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> # fbdev support Cc: Maxime Ripard <maxime@xxxxxxxxxx> Cc: Liam Girdwood <lgirdwood@xxxxxxxxx> Cc: Mark Brown <broonie@xxxxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxx> Cc: Javier Martinez Canillas <javierm@xxxxxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Cc: Peter Collingbourne <pcc@xxxxxxxxxx> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: <stable@xxxxxxxxxxxxxxx> # v5.14+ Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20210928145243.1098064-1-arnd@xxxxxxxxxx Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/of/base.c | 1 + drivers/video/fbdev/Kconfig | 5 +++-- 2 files changed, 4 insertions(+), 2 deletions(-) --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -36,6 +36,7 @@ LIST_HEAD(aliases_lookup); struct device_node *of_root; EXPORT_SYMBOL(of_root); struct device_node *of_chosen; +EXPORT_SYMBOL(of_chosen); struct device_node *of_aliases; struct device_node *of_stdout; static const char *of_stdout_options; --- a/drivers/video/fbdev/Kconfig +++ b/drivers/video/fbdev/Kconfig @@ -2191,8 +2191,9 @@ config FB_HYPERV This framebuffer driver supports Microsoft Hyper-V Synthetic Video. config FB_SIMPLE - bool "Simple framebuffer support" - depends on (FB = y) && !DRM_SIMPLEDRM + tristate "Simple framebuffer support" + depends on FB + depends on !DRM_SIMPLEDRM select FB_CFB_FILLRECT select FB_CFB_COPYAREA select FB_CFB_IMAGEBLIT Patches currently in stable-queue which might be from arnd@xxxxxxxx are queue-5.14/fbdev-simplefb-fix-kconfig-dependencies.patch