[PATCH] drm/nouveau: fix LEDS_CLASS=m configuration

[Arnd Bergmann <arnd@arndb.de>]

The newly introduced LED handling for nouveau fails to link when the
driver is built-in but the LED subsystem is a loadable module:

drivers/gpu/drm/nouveau/nouveau.o: In function `nouveau_do_suspend':
tvnv17.c:(.text.nouveau_do_suspend+0x10): undefined reference to `nouveau_led_suspend'
drivers/gpu/drm/nouveau/nouveau.o: In function `nouveau_do_resume':
tvnv17.c:(.text.nouveau_do_resume+0xf0): undefined reference to `nouveau_led_resume'
drivers/gpu/drm/nouveau/nouveau.o: In function `nouveau_drm_unload':
tvnv17.c:(.text.nouveau_drm_unload+0x34): undefined reference to `nouveau_led_fini'
drivers/gpu/drm/nouveau/nouveau.o: In function `nouveau_drm_load':
tvnv17.c:(.text.nouveau_drm_load+0x7d0): undefined reference to `nouveau_led_init'

This adds a separate Kconfig symbol for the LED support that
correctly tracks the dependencies.

Fixes: 8d021d71b324 ("drm/nouveau/drm/nouveau: add a LED driver for the NVIDIA logo")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/gpu/drm/nouveau/Kbuild        | 2 +-
 drivers/gpu/drm/nouveau/Kconfig       | 8 ++++++++
 drivers/gpu/drm/nouveau/nouveau_led.h | 2 +-
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/Kbuild b/drivers/gpu/drm/nouveau/Kbuild
index fde6e3656636..5e00e911daa6 100644
--- a/drivers/gpu/drm/nouveau/Kbuild
+++ b/drivers/gpu/drm/nouveau/Kbuild
@@ -22,7 +22,7 @@ nouveau-$(CONFIG_DEBUG_FS) += nouveau_debugfs.o
 nouveau-y += nouveau_drm.o
 nouveau-y += nouveau_hwmon.o
 nouveau-$(CONFIG_COMPAT) += nouveau_ioc32.o
-nouveau-$(CONFIG_LEDS_CLASS) += nouveau_led.o
+nouveau-$(CONFIG_DRM_NOUVEAU_LED) += nouveau_led.o
 nouveau-y += nouveau_nvif.o
 nouveau-$(CONFIG_NOUVEAU_PLATFORM_DRIVER) += nouveau_platform.o
 nouveau-y += nouveau_usif.o # userspace <-> nvif
diff --git a/drivers/gpu/drm/nouveau/Kconfig b/drivers/gpu/drm/nouveau/Kconfig
index 78631fb61adf..715cd6f4dc31 100644
--- a/drivers/gpu/drm/nouveau/Kconfig
+++ b/drivers/gpu/drm/nouveau/Kconfig
@@ -46,6 +46,14 @@ config NOUVEAU_DEBUG
 	  The paranoia and spam levels will add a lot of extra checks which
 	  may potentially slow down driver operation.
 
+config DRM_NOUVEAU_LED
+	bool "Support for logo LED"
+	depends on DRM_NOUVEAU && LEDS_CLASS
+	depends on !(DRM_NOUVEAU=y && LEDS_CLASS=m)
+	help
+	  Say Y here to enabling controlling the brightness of the
+	  LED behind NVIDIA logo on certain Titan cards.
+
 config NOUVEAU_DEBUG_DEFAULT
 	int "Default debug level"
 	depends on DRM_NOUVEAU
diff --git a/drivers/gpu/drm/nouveau/nouveau_led.h b/drivers/gpu/drm/nouveau/nouveau_led.h
index 187ecdb82002..9c9bb6ac938e 100644
--- a/drivers/gpu/drm/nouveau/nouveau_led.h
+++ b/drivers/gpu/drm/nouveau/nouveau_led.h
@@ -42,7 +42,7 @@ nouveau_led(struct drm_device *dev)
 }
 
 /* nouveau_led.c */
-#if IS_ENABLED(CONFIG_LEDS_CLASS)
+#if IS_ENABLED(CONFIG_DRM_NOUVEAU_LED)
 int  nouveau_led_init(struct drm_device *dev);
 void nouveau_led_suspend(struct drm_device *dev);
 void nouveau_led_resume(struct drm_device *dev);
-- 
2.9.0