ACPI: video: force native backlight on HP OMEN 16 (8A44)

The HP OMEN 16 Gaming Laptop (board name 8A44) has a mux-less hybrid
GPU configuration with AMD Rembrandt (Radeon 680M) and NVIDIA GA104
(RTX 3070 Ti). The internal eDP panel is wired to the AMD iGPU.

When Nouveau loads without GSP firmware, the ACPI video backlight
device (acpi_video0) gets registered alongside the native AMD
backlight (amdgpu_bl2). In this state, writes to amdgpu_bl2 update
the software brightness value but fail to change the physical panel
brightness.

Force native backlight to prevent acpi_video0 from registering.
Confirmed that booting with acpi_backlight=native resolves the
issue.

Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Shivam Kalra <shivamkalra98@zohomail.in>
Link: https://patch.msgid.link/20260426-omen-16-backlight-fix-v1-1-62364f268ea6@zohomail.in
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 0a3c8232d15d7a9ad5d6b9c3f5d3281da4c9a45c..458efa4fe9d4b06194d2b37d013210129b1e781e 100644 (file)
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -916,6 +916,14 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
                DMI_MATCH(DMI_PRODUCT_NAME, "82K8"),
                },
        },
+       {
+        .callback = video_detect_force_native,
+        /* HP OMEN Gaming Laptop 16-n0xxx */
+        .matches = {
+               DMI_MATCH(DMI_SYS_VENDOR, "HP"),
+               DMI_MATCH(DMI_PRODUCT_NAME, "OMEN by HP Gaming Laptop 16-n0xxx"),
+               },
+       },
 
        /*
         * x86 android tablets which directly control the backlight through