4.17-stable review patch. If anyone has any objections, please let me know.
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From: Arnd Bergmann arnd@arndb.de
[ Upstream commit 3156b53c2e2fadafa1a16412a8791b38f94b5bdc ]
When the base sun4i DRM driver is built-in but the back-end is a loadable module, we run into a link error:
drivers/gpu/drm/sun4i/sun4i_drv.o: In function `sun4i_drv_probe': sun4i_drv.c:(.text+0x60c): undefined reference to `sun4i_frontend_of_table'
The dependency is a bit tricky, the best workaround I have come up with is to use a Makefile hack to to interpret both CONFIG_DRM_SUN4I_BACKEND=m and CONFIG_DRM_SUN4I_BACKEND=y as a directive to build the front-end the same way as the main module.
Fixes: dd0421f47505 ("drm/sun4i: Add a driver for the display frontend") Link: https://lore.kernel.org/lkml/20180301091908.zcptz3ezqr2c6ly5@flea/ Signed-off-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Maxime Ripard maxime.ripard@bootlin.com Link: https://patchwork.freedesktop.org/patch/msgid/20180706142847.2032381-1-arnd@... Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/sun4i/Makefile | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/sun4i/Makefile +++ b/drivers/gpu/drm/sun4i/Makefile @@ -29,7 +29,10 @@ obj-$(CONFIG_DRM_SUN4I) += sun4i-tcon.o obj-$(CONFIG_DRM_SUN4I) += sun4i_tv.o obj-$(CONFIG_DRM_SUN4I) += sun6i_drc.o
-obj-$(CONFIG_DRM_SUN4I_BACKEND) += sun4i-backend.o sun4i-frontend.o +obj-$(CONFIG_DRM_SUN4I_BACKEND) += sun4i-backend.o +ifdef CONFIG_DRM_SUN4I_BACKEND +obj-$(CONFIG_DRM_SUN4I) += sun4i-frontend.o +endif obj-$(CONFIG_DRM_SUN4I_HDMI) += sun4i-drm-hdmi.o obj-$(CONFIG_DRM_SUN8I_DW_HDMI) += sun8i-drm-hdmi.o obj-$(CONFIG_DRM_SUN8I_MIXER) += sun8i-mixer.o