ACPI: video: Don't enable fallback path for creating ACPI backlight by default
authorMario Limonciello <mario.limonciello@amd.com>
Thu, 8 Dec 2022 16:42:07 +0000 (10:42 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 12 Jan 2023 11:02:40 +0000 (12:02 +0100)
commit9c152189a7e85dac1f759d6ba95f877af91ccf8c
treefbf8899153768c1c319cff7e3003e36c645fac9f
parentadaf41b56803fe7a9a4ac625c7e41615ef23591f
ACPI: video: Don't enable fallback path for creating ACPI backlight by default

[ Upstream commit 5aa9d943e9b6bf6e6023645cbe7ce7d5ed84baf4 ]

The ACPI video detection code has a module parameter
`register_backlight_delay` which is currently configured to 8 seconds.
This means that if after 8 seconds of booting no native driver has created
a backlight device then the code will attempt to make an ACPI video
backlight device.

This was intended as a safety mechanism with the backlight overhaul that
occurred in kernel 6.1, but as it doesn't appear necesssary set it to be
disabled by default.

Suggested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-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>
drivers/acpi/acpi_video.c