Just like many other Samsung models, the 670Z5E needs to use the acpi-video backlight interface rather then the native one for backlight control to work, add a quirk for this. Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1557060 Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- drivers/acpi/video_detect.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c index 601e5d372887..43587ac680e4 100644 --- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -219,6 +219,15 @@ static const struct dmi_system_id video_detect_dmi_table[] = { "3570R/370R/470R/450R/510R/4450RV"), }, }, + { + /* https://bugzilla.redhat.com/show_bug.cgi?id=1557060 */ + .callback = video_detect_force_video, + .ident = "SAMSUNG 670Z5E", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."), + DMI_MATCH(DMI_PRODUCT_NAME, "670Z5E"), + }, + }, { /* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */ .callback = video_detect_force_video, -- 2.14.3