> ## Documentation Index > Fetch the complete documentation index at: https://dragonwingdocs.qualcomm.com/llms.txt > Use this file to discover all available pages before exploring further. # Display The IQ-9075 platform features a Qualcomm Adreno Display Processing Unit (DPU) providing hardware-accelerated image processing. The IQ9-EVK supports two simultaneous displays via dual DisplayPort outputs. ## Display Capabilities | Interface | Capability | | -------------- | --------------------------------------------------------------- | | **DP0** | 3840 × 2160 at 60 fps, 30 bpp | | **DP1** | 3840 × 2160 at 60 fps, 30 bpp | | **Concurrent** | DP0 as primary + DP1 as secondary, both at 3840 × 2160 @ 60 fps | **Supported features:** * Wayland and Weston with upstream protocol * Weston compositor with DRM backend * 2× DisplayPort with SST and MST support ## Architecture ### DPU Hardware | Component | Function | | ---------------------------------- | ------------------------------------------------------- | | **Bus Interface** | Fetches data from memory | | **Source Surface Processing** | Reads RGB/YUV surfaces; performs format conversion | | **Blending** | Blends and mixes source surfaces | | **Destination Surface Processing** | Converts and adjusts data for panel characteristics | | **Compression** | Reduces bandwidth by sending compressed display buffers | | **Display Interface** | Generates timings for connected display peripherals | ### Software Stack | Component | Description | | --------------------- | -------------------------------------------------------------- | | **Wayland Sink** | Plug-in communicating with Weston to render the display | | **Weston** | Wayland compositor; handles composition and rendering | | **DRM Backend** | Manages Adreno DPU hardware resources and composition strategy | | **libdrm** | Library providing DRM IOCTL APIs | | **DRM/KMS Framework** | Kernel and userland interface for hardware features | | **Adreno DPU Driver** | Manages all pixel data paths to panel interfaces | ## DisplayPort and DSI Interfaces ### eDP Interface The processor has four eDP interfaces. eDP0 and eDP1 are routed to connectors JEDP0 and JEDP1. ### DSI Interface The IQ-9075 supports two 4-lane MIPI-DSI with VESA DSC v1.2. The DSI0 interface uses an analog switch allowing access through both the JDISP LCD connector and the JEXP1 board-to-board expansion connector. ## Setup ### Connect DisplayPort Connect a DisplayPort cable to the **eDP0** connector. For dual display, connect a second DisplayPort cable to **eDP1**. Power on the device. Weston launches automatically during boot and displays the flower pattern. ### SSH Access Default credentials: **Username:** `ubuntu` / **Password:** `ubuntu` ## Testing and Verification ### Run Weston EGL Client ```bash theme={null} weston-simple-egl ``` **Expected output:** A rotating triangle on the display at 60 fps. ``` 300 frames in 5 seconds: 60.000000 fps ``` Press `Ctrl+C` to terminate. ### GStreamer Video Playback Ensure video files are at `/etc/media` on the device. ```bash theme={null} # H.264 playback gst-launch-1.0 -v filesrc location=/etc/media/video.mp4 ! qtdemux ! queue ! \ h264parse ! v4l2h264dec capture-io-mode=4 output-io-mode=4 ! \ video/x-raw,format=NV12 ! waylandsink # H.265/HEVC playback gst-launch-1.0 -v filesrc location=/etc/media/video_hevc.mp4 ! qtdemux ! queue ! \ h265parse ! v4l2h265dec capture-io-mode=4 output-io-mode=4 ! \ video/x-raw,format=NV12 ! waylandsink # With scaling gst-launch-1.0 -v filesrc location=/etc/media/video.mp4 ! qtdemux ! queue ! \ h264parse ! v4l2h264dec capture-io-mode=4 output-io-mode=4 ! \ video/x-raw,width=1920,height=1080 ! waylandsink ``` **Key pipeline components:** | Component | Purpose | | ------------------- | --------------------------------------------------------- | | `capture-io-mode=4` | Allocates decoded frames as DMABUF (zero-copy to display) | | `output-io-mode=4` | Handles encoded bitstream buffers via DMABUF | | `format=NV12` | NV12 pixel format for hardware-accelerated path | | `waylandsink` | Renders video to Wayland display | ## Debugging ### Check DisplayPort Status ```bash theme={null} # Cable status sudo cat /sys/class/drm/card0-DP-1/status # eDP0 sudo cat /sys/class/drm/card0-DP-2/status # eDP1 # Available modes (EDID) sudo cat /sys/class/drm/card0-DP-1/modes # Detailed DP info sudo cat /sys/kernel/debug/dri/0/DP-1/dp_debug ``` ### Debug Filesystem | Command | Purpose | | ----------------------------------- | ------------------------------- | | `dmesg \| grep -i display` | Display-related kernel messages | | `dmesg \| grep -i drm` | DRM subsystem messages | | `cat /sys/kernel/debug/dri/0/state` | Current DRM state | | `cat /proc/interrupts \| grep mdss` | Display interrupts | ## Troubleshooting ```bash theme={null} cat /sys/class/drm/card0-DP-1/status sudo dmesg | grep -i "dp\|display\|drm" ``` * Verify cable connection to eDP0 or eDP1 * Check display power and input source selection ```bash theme={null} cat /sys/class/drm/card0-DP-1/modes ``` Verify the display supports the desired resolution. ```bash theme={null} journalctl -u weston ls -l /dev/dri/card0 ls -l /dev/dri/ ``` Manually launch Weston with debug output: ```bash theme={null} weston --idle-time=0 --continue-without-input --log=/home/ubuntu/weston.log ``` ```bash theme={null} cat /sys/class/drm/card0-DP-1/status cat /sys/class/drm/card0-DP-2/status cat /sys/kernel/debug/dri/0/state ``` * Verify both cables are connected to eDP0 and eDP1 * Check Weston configuration for multi-display support ```bash theme={null} ps -A | grep weston killall weston sudo systemctl start weston-autostart export XDG_RUNTIME_DIR=/run/user/$(id -u ubuntu) export WAYLAND_DISPLAY=wayland-1 ``` ## Resources | Resource | URL | | ------------------------- | -------------------------------------------------------------------------------------------------------------------------- | | DRM Internals | [https://www.kernel.org/doc/html/v5.4/gpu/drm-internals.html](https://www.kernel.org/doc/html/v5.4/gpu/drm-internals.html) | | Kernel Mode Setting (KMS) | [https://www.kernel.org/doc/html/v5.4/gpu/drm-kms.html](https://www.kernel.org/doc/html/v5.4/gpu/drm-kms.html) | | Wayland Protocol | [https://wayland.freedesktop.org/](https://wayland.freedesktop.org/) | | Weston Compositor | [https://gitlab.freedesktop.org/wayland/weston](https://gitlab.freedesktop.org/wayland/weston) | | GStreamer Documentation | [https://gstreamer.freedesktop.org/documentation/](https://gstreamer.freedesktop.org/documentation/) |