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[v2,05/29] drm/nouveau: Don't register backlight when another backlight should be used

Message ID 20220712193910.439171-6-hdegoede@redhat.com
State Superseded
Headers show
Series [v2,01/29] ACPI: video: Add acpi_video_backlight_use_native() helper | expand

Commit Message

Hans de Goede July 12, 2022, 7:38 p.m. UTC 
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.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/gpu/drm/nouveau/nouveau_backlight.c | 7 +++++++
 1 file changed, 7 insertions(+)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index a2141d3d9b1d..91c504c7b82c 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"
@@ -405,6 +407,11 @@  nouveau_backlight_init(struct drm_connector *connector)
 		goto fail_alloc;
 	}
 
+	if (!acpi_video_backlight_use_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;