Before this commit when we want userspace to use the acpi_video backlight device we register both the GPU's native backlight device and acpi_video's firmware acpi_video# backlight device. This relies on userspace preferring firmware type backlight devices over native ones.
Registering 2 backlight devices for a single display really is undesirable, don't register the GPU's native backlight device when another backlight device should be used.
Signed-off-by: Hans de Goede hdegoede@redhat.com --- drivers/gpu/drm/nouveau/nouveau_backlight.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c index daf9f87477ba..f56ff797c78c 100644 --- a/drivers/gpu/drm/nouveau/nouveau_backlight.c +++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c @@ -34,6 +34,8 @@ #include <linux/backlight.h> #include <linux/idr.h>
+#include <acpi/video.h> + #include "nouveau_drv.h" #include "nouveau_reg.h" #include "nouveau_encoder.h" @@ -404,6 +406,11 @@ nouveau_backlight_init(struct drm_connector *connector) goto fail_alloc; }
+ if (acpi_video_get_backlight_type(true) != acpi_backlight_native) { + NV_INFO(drm, "Skipping nv_backlight registration\n"); + goto fail_alloc; + } + if (!nouveau_get_backlight_name(backlight_name, bl)) { NV_ERROR(drm, "Failed to retrieve a unique name for the backlight interface\n"); goto fail_alloc;