[Intel-gfx] [PATCH v2 02/29] drm/i915: Don't register backlight when another backlight should be used

Hans de Goede
2022-07-12T19:39:37Z

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/i915/display/intel_backlight.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_backlight.c b/drivers/gpu/drm/i915/display/intel_backlight.c
index 110fc98ec280..567943c9ffbc 100644
--- a/drivers/gpu/drm/i915/display/intel_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_backlight.c
@@ -8,6 +8,8 @@
#include <linux/pwm.h>
#include <linux/string_helpers.h>

+#include <acpi/video.h>
+
#include "intel_backlight.h"
#include "intel_connector.h"
#include "intel_de.h"
@@ -950,6 +952,11 @@ int intel_backlight_device_register(struct intel_connector *connector)

WARN_ON(panel->backlight.max == 0);

+ if (!acpi_video_backlight_use_native()) {
+ DRM_INFO("Skipping intel_backlight registration\n");
+ return 0;
+ }
+
memset(&props, 0, sizeof(props));
props.type = BACKLIGHT_RAW;

--
2.36.0