From: Arnd Bergmann arnd@arndb.de
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") Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/of/base.c | 1 + drivers/video/fbdev/Kconfig | 5 +++-- 2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/of/base.c b/drivers/of/base.c index 48e941f99558..073ea7cd007b 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; diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig index 8a98539ec490..5fbcb3cc2e8e 100644 --- a/drivers/video/fbdev/Kconfig +++ b/drivers/video/fbdev/Kconfig @@ -2207,8 +2207,9 @@ 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