acpi-video is unique in that it not only generates brightness up/down
keypresses, but also (sometimes) actively changes the brightness itself.
This presents an inconsistent kernel interface to userspace, basically there
are 2 different scenarios, depending on the laptop model:
1) On some laptops a brightness up/down keypress means: show a brightness osd
with the current brightness, iow it is a brightness has changed notification.
2) Where as on (a lot of) other laptops it means a brightness up/down key was
pressed, deal with it.
Most of the desktop environments interpret any press as in scenario 2, and
change the brightness up / down as a response to the key events, causing it
to be changed twice, once by acpi-video and once by the DE.
With the new default for video.use_native_backlight we will be moving even
more laptops over to behaving as in scenario 2. Making the remaining laptops
even more of a weird exception. Also note that it is hard to detect scenario
1 properly in userspace, and AFAIK none of the DE-s deals with it.
Therefor this commit changes the default of brightness_switch_enabled to 0
making its behavior consistent with all the other backlight drivers.
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/acpi/video.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index cebc74d..34198b2 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -68,7 +68,7 @@ MODULE_AUTHOR("Bruno Ducrot");
MODULE_DESCRIPTION("ACPI Video Driver");
MODULE_LICENSE("GPL");
-static bool brightness_switch_enabled = 1;
+static bool brightness_switch_enabled;
module_param(brightness_switch_enabled, bool, 0644);
/*
--
1.9.0
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