@@ -82,6 +82,7 @@ MODULE_PARM_DESC(register_backlight_delay,
static bool may_report_brightness_keys;
static int register_count;
+static bool native_reported_nolcd;
static DEFINE_MUTEX(register_count_mutex);
static DEFINE_MUTEX(video_list_lock);
static LIST_HEAD(video_bus_head);
@@ -1811,6 +1812,9 @@ static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
return false;
}
+ if (native_reported_nolcd)
+ return false;
+
if (only_lcd)
return dev->flags.lcd;
return true;
@@ -2178,6 +2182,14 @@ static bool should_check_lcd_flag(void)
return false;
}
+void acpi_video_report_nolcd(void)
+{
+ /* Only take into account native driver reporting on desktops */
+ if (dmi_is_desktop())
+ native_reported_nolcd = true;
+}
+EXPORT_SYMBOL(acpi_video_report_nolcd);
+
int acpi_video_register(void)
{
int ret = 0;
@@ -53,6 +53,7 @@ enum acpi_backlight_type {
};
#if IS_ENABLED(CONFIG_ACPI_VIDEO)
+extern void acpi_video_report_nolcd(void);
extern int acpi_video_register(void);
extern void acpi_video_unregister(void);
extern void acpi_video_register_backlight(void);
The current logic for the ACPI backlight detection will create a backlight device if no native or vendor drivers have created 8 seconds after the system has booted if the ACPI tables included backlight control methods. If the GPU drivers have loaded, they may be able to report whether any LCD panels were found. Allow using this information to factor in whether to make an acpi_video0 backlight device. To avoid risks for regressions on complicated configurations with muxes and multiple native drivers, only take into account drivers that have reported this when the system is a desktop. Suggested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> --- drivers/acpi/acpi_video.c | 12 ++++++++++++ include/acpi/video.h | 1 + 2 files changed, 13 insertions(+)