shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-03-24 19:40:21 +09:00
Code Issues Packages Projects Releases Wiki Activity

ACPI: video: Prefer native over vendor

Browse Source 
[ Upstream commit fb1836c913 ]

When available prefer native backlight control over vendor backlight
control.

Testing has shown that there are quite a few laptop models which rely
on native backlight control (they don't have ACPI video bus backlight
control) and on which acpi_osi_is_win8() returns false.

Currently __acpi_video_get_backlight_type() returns vendor on these
laptops, leading to an empty /sys/class/backlight.

As a workaround for this acpi_video_backlight_use_native() has been
temporarily changed to always return true.

This re-introduces the problem of having multiple backlight
devices under /sys/class/backlight for a single panel.

Change __acpi_video_get_backlight_type() to prefer native over vendor
when available. So that it returns native on these models.

And change acpi_video_backlight_use_native() back to only return
true when __acpi_video_get_backlight_type() returns native.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Hans de Goede
2022-11-14 15:44:59 +01:00
committed by Greg Kroah-Hartman
parent 923c1922bd
commit 8af3d02aae
1 changed files with 3 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
drivers/acpi/video_detect.c
View File

@@ -795,10 +795,10 @@ static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
return acpi_backlight_video;
/* Use native if available */
if (native_available && prefer_native_over_acpi_video())
if (native_available)
return acpi_backlight_native;
/* No ACPI video (old hw), use vendor specific fw methods. */
/* No ACPI video/native (old hw), use vendor specific fw methods. */
return acpi_backlight_vendor;
}
@@ -810,18 +810,6 @@ EXPORT_SYMBOL(acpi_video_get_backlight_type);
bool acpi_video_backlight_use_native(void)
{
/*
* Call __acpi_video_get_backlight_type() to let it know that
* a native backlight is available.
*/
__acpi_video_get_backlight_type(true);
/*
* For now just always return true. There is a whole bunch of laptop
* models where (video_caps & ACPI_VIDEO_BACKLIGHT) is false causing
* __acpi_video_get_backlight_type() to return vendor, while these
* models only have a native backlight control.
*/
return true;
return __acpi_video_get_backlight_type(true) == acpi_backlight_native;
}
EXPORT_SYMBOL(acpi_video_backlight_use_native);