drm/nouveau: don't expose backlight control when available through ACPI
Avoid confusing userspace by not publishing backlight controls if ACPI
equivalents are available.
Reported-by: Aaron Sowry <aaron@aeneby.se>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index 406228f..b14c811 100644
--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -31,6 +31,7 @@
*/
#include <linux/backlight.h>
+#include <linux/acpi.h>
#include "drmP.h"
#include "nouveau_drv.h"
@@ -136,6 +137,14 @@
{
struct drm_nouveau_private *dev_priv = dev->dev_private;
+#ifdef CONFIG_ACPI
+ if (acpi_video_backlight_support()) {
+ NV_INFO(dev, "ACPI backlight interface available, "
+ "not registering our own\n");
+ return 0;
+ }
+#endif
+
switch (dev_priv->card_type) {
case NV_40:
return nouveau_nv40_backlight_init(dev);