Default backlight interface is AMD's radeon_bl0 which does not work on this system. As a result, let's for ACPI backlight interface for this system. BugLink: https://bugs.launchpad.net/bugs/1894667 Cc: All applicable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Alex Hung <alex.hung@xxxxxxxxxxxxx> --- 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 2499d7e..05047a3 100644 --- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -282,6 +282,15 @@ static const struct dmi_system_id video_detect_dmi_table[] = { DMI_MATCH(DMI_PRODUCT_NAME, "530U4E/540U4E"), }, }, + /* https://bugs.launchpad.net/bugs/1894667 */ + { + .callback = video_detect_force_video, + .ident = "HP 635 Notebook", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), + DMI_MATCH(DMI_PRODUCT_NAME, "HP 635 Notebook PC"), + }, + }, /* Non win8 machines which need native backlight nevertheless */ { -- 2.7.4
