CQ2390M/CQ2390S - Qualcomm Dragonwing Documentation

Debug the DSI display

You must enable SSH to access your host device. For instructions, see Sign in using SSH.
To mount the debugfs file system and access display subsystem debug information, run the following commands:

mount -o remount,rw /

mount -t debugfs none /sys/kernel/debug

View the DSI display status To check the DSI connector status, run the following command:

cat /sys/class/drm/card0-DSI-1/status

Sample output

connected

Check the display mode To check the active display mode, run the following command:

cat /sys/class/drm/card0-DSI-1/modes

Sample output

1080x1920

View the DRM state To check the DRM connector and encoder state, run the following command:

cat /sys/kernel/debug/dri/0/state

Sample output

connector[32]: DSI-1
        status: connected
        encoder: 31
crtc[30]: crtc-0
        active=yes
        self_refresh_active=no
        planes:
encoder[31]: DSI-1
        crtc: crtc-0

View the DPU debug information To check the DPU debug information, run the following command:

cat /sys/kernel/debug/dri/0/debug/core_perf_core_clk_rate

Check the Weston service status To verify that Weston is running, run the following command:

systemctl status weston

Sample output

● weston.service - Weston Wayland Compositor
     Loaded: loaded
     Active: active (running)

Relaunch Weston If the display is not active, stop and restart the Weston service:

systemctl stop weston.socket weston.service

systemctl start weston.service

For more information on relaunching Weston, see Relaunch Weston.

​Debug the DSI display

Debug the DSI display