On Mon, Sep 14, 2020 at 12:34 AM Alex Hung alex.hung@canonical.com wrote:

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: stable@vger.kernel.org Signed-off-by: Alex Hung alex.hung@canonical.com

---

V2: correct Cc to stable

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 */
    {
  

--

Applied as 5.10 material, thanks!