From 0ba8892d86ad69775e4ee3de53b021ae33aca8c0 Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Thu, 8 Dec 2022 10:42:05 -0600 Subject: [PATCH] ACPI: video: Allow GPU drivers to report no panels [ Upstream commit 00a734104af7d878f1252d49eff9298785c6cbdc ] 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 enable the fallback logic for making an acpi_video0 backlight device. Suggested-by: Hans de Goede Signed-off-by: Mario Limonciello Reviewed-by: Hans de Goede Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/acpi/acpi_video.c | 11 +++++++++++ include/acpi/video.h | 2 ++ 2 files changed, 13 insertions(+) diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c index 3295364..f64fdb0 100644 --- a/drivers/acpi/acpi_video.c +++ b/drivers/acpi/acpi_video.c @@ -2178,6 +2178,17 @@ static bool should_check_lcd_flag(void) return false; } +/* + * At least one graphics driver has reported that no LCD is connected + * via the native interface. cancel the registration for fallback acpi_video0. + * If another driver still deems this necessary, it can explicitly register it. + */ +void acpi_video_report_nolcd(void) +{ + cancel_delayed_work(&video_bus_register_backlight_work); +} +EXPORT_SYMBOL(acpi_video_report_nolcd); + int acpi_video_register(void) { int ret = 0; diff --git a/include/acpi/video.h b/include/acpi/video.h index a275c35..8ed9bec 100644 --- a/include/acpi/video.h +++ b/include/acpi/video.h @@ -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); @@ -69,6 +70,7 @@ extern int acpi_video_get_levels(struct acpi_device *device, struct acpi_video_device_brightness **dev_br, int *pmax_level); #else +static inline void acpi_video_report_nolcd(void) { return; }; static inline int acpi_video_register(void) { return -ENODEV; } static inline void acpi_video_unregister(void) { return; } static inline void acpi_video_register_backlight(void) { return; } -- 2.7.4