fbdev: Make fb-notify a no-op if CONFIG_FB=n

There's no point in having support for framebuffer notifications
is CONFIG_FB is disabled. This commit adds the necessary stubs
for code to link properly when CONFIG_FB=n and moves fb-notify.o
to be built only when CONFIG_FB=y.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

3 files changed, 23 insertions, 1 deletions

diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index 1727a964aea5..d43f27682d02 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig
@@ -5,6 +5,7 @@
 menuconfig FB
         tristate "Support for frame buffer devices"
         select FB_CMDLINE
+        select FB_NOTIFY
         ---help---
           The frame buffer device provides an abstraction for the graphics
           hardware. It represents the frame buffer of some video hardware and
@@ -56,6 +57,9 @@ config FIRMWARE_EDID
 config FB_CMDLINE
         bool
 
+config FB_NOTIFY
+        bool
+
 config FB_DDC
        tristate
        depends on FB
diff --git a/drivers/video/fbdev/core/Makefile b/drivers/video/fbdev/core/Makefile
index 23d86a8b7d7b..9e3ddf225393 100644
--- a/drivers/video/fbdev/core/Makefile
+++ b/drivers/video/fbdev/core/Makefile
@@ -1,5 +1,5 @@
-obj-y                             += fb_notify.o
 obj-$(CONFIG_FB_CMDLINE)          += fb_cmdline.o
+obj-$(CONFIG_FB_NOTIFY)           += fb_notify.o
 obj-$(CONFIG_FB)                  += fb.o
 fb-y                              := fbmem.o fbmon.o fbcmap.o fbsysfs.o \
                                      modedb.o fbcvt.o
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 3d003805aac3..55433f86f0a3 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -175,9 +175,27 @@ struct fb_blit_caps {
         u32 flags;
 };
 
+#ifdef CONFIG_FB_NOTIFY
 extern int fb_register_client(struct notifier_block *nb);
 extern int fb_unregister_client(struct notifier_block *nb);
 extern int fb_notifier_call_chain(unsigned long val, void *v);
+#else
+static inline int fb_register_client(struct notifier_block *nb)
+{
+        return 0;
+};
+
+static inline int fb_unregister_client(struct notifier_block *nb)
+{
+        return 0;
+};
+
+static inline int fb_notifier_call_chain(unsigned long val, void *v)
+{
+        return 0;
+};
+#endif
+
 /*
  * Pixmap structure definition
  *