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authorHans de Goede <hdegoede@redhat.com>2023-10-26 15:53:03 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2023-11-20 17:47:07 +0100
commit52304886ea49ee662589aff05925ef226c17a6a6 (patch)
tree97fbf56068c5ba04e89b0c6a35d0f364f62a6ecf /include/acpi/video.h
parentc93695494606326d7fd72b46a2a657139ccb0dec (diff)
ACPI: video: Add comment about acpi_video_backlight_use_native() usage
Add a comment explaining that acpi_video_backlight_use_native() MUST only be used by GPU drivers and that it must NOT be used on other places. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'include/acpi/video.h')
-rw-r--r--include/acpi/video.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/include/acpi/video.h b/include/acpi/video.h
index 4230392b5b0b..3d538d4178ab 100644
--- a/include/acpi/video.h
+++ b/include/acpi/video.h
@@ -75,6 +75,15 @@ static inline enum acpi_backlight_type acpi_video_get_backlight_type(void)
return __acpi_video_get_backlight_type(false, NULL);
}
+/*
+ * This function MUST only be called by GPU drivers to check if the driver
+ * should register a backlight class device. This function not only checks
+ * if a GPU native backlight device should be registered it *also* tells
+ * the ACPI video-detect code that native GPU backlight control is available.
+ * Therefor calling this from any place other then the GPU driver is wrong!
+ * To check if GPU native backlight control is used in other places instead use:
+ * if (acpi_video_get_backlight_type() == acpi_backlight_native) { ... }
+ */
static inline bool acpi_video_backlight_use_native(void)
{
return __acpi_video_get_backlight_type(true, NULL) == acpi_backlight_native;