acpi: add a way to promote/demote vendor backlight drivers
Instead of adding a big blacklist in video_detect.c to set
ACPI_VIDEO_BACKLIGHT_DMI_VENDOR correctly, let external modules
promote or demote themselves when they know the generic video
module won't work.
Currently drivers where using acpi_video_unregister() directly
but:
- That didn't respect any acpi_backlight=[video|vendor] parameter
provided by the user.
- Any later call to acpi_video_register() would still re-load the
generic video module (and some gpu drivers are doing that).
This patch fix those two issues.
Signed-off-by: Corentin Chary <corentin.chary@gmail.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index f421dd8..27ab201 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -190,6 +190,8 @@
extern long acpi_video_get_capabilities(acpi_handle graphics_dev_handle);
extern long acpi_is_video_device(struct acpi_device *device);
+extern void acpi_video_dmi_promote_vendor(void);
+extern void acpi_video_dmi_demote_vendor(void);
extern int acpi_video_backlight_support(void);
extern int acpi_video_display_switch_support(void);
@@ -205,6 +207,14 @@
return 0;
}
+static inline void acpi_video_dmi_promote_vendor(void)
+{
+}
+
+static inline void acpi_video_dmi_demote_vendor(void)
+{
+}
+
static inline int acpi_video_backlight_support(void)
{
return 0;