I have tested these panels on the Framework Laptop 13 AMD with firmware
revision 3.05 (latest at time of submission).
Signed-off-by: Dustin L. Howett <dustin@howett.net>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241111-amdgpu-min-backlight-quirk-v7-4-f662851fda69@weissschuh.net
The value of "min_input_signal" returned from ATIF on a Framework AMD 13
is "12". This leads to a fairly bright minimum display backlight.
Add a quirk to override that the minimum backlight PWM to "0" which
leads to a much lower minimum brightness, which is still visible.
Tested on a Framework AMD 13 BIOS 3.05 with the matte panel.
Link: https://community.frame.work/t/25711/9
Link: https://community.frame.work/t/47036
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Dustin L. Howett <dustin@howett.net>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241111-amdgpu-min-backlight-quirk-v7-3-f662851fda69@weissschuh.net
Panels using a PWM-controlled backlight source do not have a standard
way to communicate their valid PWM ranges.
On x86 the ranges are read from ACPI through driver-specific tables.
The built-in ranges are not necessarily correct, or may grow stale if an
older device can be retrofitted with newer panels.
Add a quirk infrastructure with which the minimum valid backlight value
can be maintained as part of the kernel.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Dustin L. Howett <dustin@howett.net>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241111-amdgpu-min-backlight-quirk-v7-1-f662851fda69@weissschuh.net
