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

commit 4b506ea upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: shivamklr

drivers/acpi/video_detect.c

@@ -820,6 +820,14 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 		DMI_MATCH(DMI_PRODUCT_NAME, "Z830"),
 		},
 	},
+	{
+	 .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"),
+		},
+	},
 
 	/*
 	 * Models which have nvidia-ec-wmi support, but should not use it.