Dear Maintainer,

Problem

The physical HDMI port is not detected or exposed in `xrandr`.
Only the internal panel (eDP-1) and my DisplayLink adapter (DVI-I-1 via evdi)
appear.

- `xrandr --listproviders` → `Providers: number : 0`
- `xrandr --query | grep -i hdmi` → no output
- `dmesg | grep -i drm` shows i915 and amdgpu initializing without errors, but
no HDMI connector registered
- Only HDMI audio devices appear (`HDA Intel HDMI HDMI/DP,pcm=3…`) in kernel
log

Expected

The HDMI connector (wired to the AMD GPU in this model) should appear as
`HDMI-A-0` (or similar) and allow an external monitor to be used via PRIME
outputs.

Steps tried

- Ensured `xserver-xorg-video-amdgpu` installed
- Tested both Wayland and Xorg sessions
- Forced dGPU runtime power to "on"
(`/sys/bus/pci/devices/0000:03:00.0/power/control`)
- Added simple Xorg configs for Intel (modesetting) and AMD (amdgpu)
- Still: HDMI output never listed by `xrandr`

Notes

- DisplayLink external monitor works fine (DVI-I-1).
- This appears to be specific to the hybrid Intel + AMD Topaz configuration on
the Dell Inspiron 5547.

Request

Please advise whether this is a regression in amdgpu / modesetting PRIME
outputs, a missing quirk for Topaz dGPU HDMI routing, or misconfiguration. Any
guidance on patches, debug flags or extra logs to collect is appreciated.

Hardware

- Laptop: Dell Inspiron 15 5547
- CPU/GPU: Intel Core i7-4510U with integrated Intel HD Graphics 4400 (i915)
- dGPU: AMD Radeon R7 M260/M265 (Topaz, PCI ID 1002:6900, driver amdgpu)
- Display: internal panel (eDP-1) + HDMI port connected to external monitor
- Kernel: Linux 6.12.38 (Debian testing, August 2025)
- BIOS: Dell A13 (2019-05-27)

Software

- xserver-xorg-video-intel 2:2.99.917+git20210115-1
- xserver-xorg-video-amdgpu (installed)
- mesa 25.0.7
- session: both Wayland and "GNOME on Xorg" tested

After the system update on 2025-09-01, the issue with the HDMI output
not being detected was resolved.

Previously, only eDP-1 and DVI-I-1 were listed, while HDMI-1 was
missing. After the updates, the HDMI-connected monitor is now correctly
recognized and working.

Packages updated that most likely fixed the problem:

     Kernel

         linux-image-amd64 upgraded from 6.12.38-1 to 6.16.3-1

         linux-headers-amd64 upgraded from 6.12.38-1 to 6.16.3-1

         New packages: linux-image-6.16.3+deb14-amd64 and linux-headers-6.16.3+deb14-*

     DRM stack

         libdrm2:amd64 2.4.125-2

         libdrm-amdgpu1:amd64 2.4.125-2

         libdrm-intel1:amd64 2.4.125-2

         libdrm-radeon1:amd64 2.4.125-2

Conclusion

Here, the bug was fixed by the combined update of the kernel and the DRM
graphics stack. The HDMI output (HDMI-1) is now properly listed by
xrandr, and the external monitor works as expected.