When video.use_native_backlight=1 and non intel gfx are in use, the raw
backlight device of the gfx driver will show up after acpi-video has done its
acpi_video_verify_backlight_support() check.
This causes video.use_native_backlight=1 to not have the desired result.
This patch fixes this by adding a backlight notifier and when a raw
backlight is registered or unregistered re-doing the
acpi_video_verify_backlight_support() check.
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
drivers/acpi/video.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 57 insertions(+)
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index ba6e4d7..47b7e21 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -151,6 +151,7 @@ struct acpi_video_enumerated_device {
struct acpi_video_bus {
struct acpi_device *device;
bool backlight_registered;
+ bool backlight_notifier_registered;
u8 dos_setting;
struct acpi_video_enumerated_device *attached_array;
u8 attached_count;
@@ -162,6 +163,7 @@ struct acpi_video_bus {
struct input_dev *input;
char phys[32]; /* for input device */
struct notifier_block pm_nb;
+ struct notifier_block backlight_nb;
};
struct acpi_video_device_flags {
@@ -1828,6 +1830,9 @@ static int acpi_video_bus_register_backlight(struct
acpi_video_bus *video)
{
struct acpi_video_device *dev;
+ if (video->backlight_registered)
+ return 0;
+
if (!acpi_video_verify_backlight_support())
return 0;
@@ -1972,6 +1977,56 @@ static void acpi_video_bus_remove_notify_handler(struct
acpi_video_bus *video)
video->input = NULL;
}
+static int acpi_video_backlight_notify(struct notifier_block *nb,
+ unsigned long val, void *bd)
+{
+ struct backlight_device *backlight = bd;
+ struct acpi_video_bus *video;
+
+ /* acpi_video_verify_backlight_support only cares about raw devices */
+ if (backlight->props.type != BACKLIGHT_RAW)
+ return NOTIFY_DONE;
+
+ video = container_of(nb, struct acpi_video_bus, backlight_nb);
+
+ switch (val) {
+ case BACKLIGHT_REGISTERED:
+ if (!acpi_video_verify_backlight_support())
+ acpi_video_bus_unregister_backlight(video);
+ break;
+ case BACKLIGHT_UNREGISTERED:
+ acpi_video_bus_register_backlight(video);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static int acpi_video_bus_add_backlight_notify_handler(
+ struct acpi_video_bus *video)
+{
+ int error;
+
+ video->backlight_nb.notifier_call = acpi_video_backlight_notify;
+ video->backlight_nb.priority = 0;
+ error = backlight_register_notifier(&video->backlight_nb);
+ if (error == 0)
+ video->backlight_notifier_registered = true;
+
+ return error;
+}
+
+static int acpi_video_bus_remove_backlight_notify_handler(
+ struct acpi_video_bus *video)
+{
+ if (!video->backlight_notifier_registered)
+ return 0;
+
+ video->backlight_notifier_registered = false;
+
+ return backlight_unregister_notifier(&video->backlight_nb);
+}
+
static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
{
struct acpi_video_device *dev, *next;
@@ -2053,6 +2108,7 @@ static int acpi_video_bus_add(struct acpi_device *device)
acpi_video_bus_register_backlight(video);
acpi_video_bus_add_notify_handler(video);
+ acpi_video_bus_add_backlight_notify_handler(video);
return 0;
@@ -2076,6 +2132,7 @@ static int acpi_video_bus_remove(struct acpi_device
*device)
video = acpi_driver_data(device);
+ acpi_video_bus_remove_backlight_notify_handler(video);
acpi_video_bus_remove_notify_handler(video);
acpi_video_bus_unregister_backlight(video);
acpi_video_bus_put_devices(video);
--
1.9.0
