From ec7cc3f74b4236860ce612656aa5be7936d1c594 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 28 Sep 2021 16:52:10 +0200 Subject: fbdev: simplefb: fix Kconfig dependencies 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 # for drivers/of/ Link: https://lore.kernel.org/all/20210721151839.2484245-1-arnd@kernel.org/ Signed-off-by: Arnd Bergmann Cc: Thomas Zimmermann Cc: Daniel Vetter # fbdev support Cc: Maxime Ripard Cc: Liam Girdwood Cc: Mark Brown Cc: Daniel Vetter Cc: Borislav Petkov Cc: Javier Martinez Canillas Cc: Randy Dunlap Cc: Geert Uytterhoeven Cc: Peter Collingbourne Cc: Andy Shevchenko Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Cc: # v5.14+ Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20210928145243.1098064-1-arnd@kernel.org Signed-off-by: Maarten Lankhorst --- drivers/of/base.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/of/base.c') diff --git a/drivers/of/base.c b/drivers/of/base.c index f720c0d246f2..0ac17256258d 100644 --- 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; -- cgit v1.2.3-58-ga151