Debug the DSI display
The DSI0 panel connects through the EVKâs CTP display daughtercard and maps toDSI-1. Its direct panel path determines the DSI clock and driver names used in steps 4 and 5.
Before running the software checks, verify the connections and default display-switch positions in CQ2390 DSI display setup. Power off the EVK before reseating the panel cable or changing switches.
Table: Display hardware checks
Connect to the target through SSH and run target commands from the root shell. For instructions, see Sign in using SSH.
1. Identify the connector
Run the following command:
This lists the DSI connector, its DRM ID, and its connection state.
2. Check connector status and modes
Run the following command:Run the following command:A connected panel must report one or more modes. If
This reports whether the panel is connected. The expected result is
connected.Reference output
This lists the modes reported by the panel.
Reference output
card0 is absent, use the DRM card reported by modetest. A connected state alone does not verify the physical panel connection or backlight power. Check the FPC cable and EVK routing even when DRM reports the fixed DSI panel as connected.3. Check the active DRM state
If For
debugfs is not mounted, run the following command:This makes DRM state and interface debug data available. Run the following command:
This shows the DSI encoder, CRTC, mode, and plane. Run the following command:
This shows the kernel DRM connector, encoder, CRTC, and plane state.
Reference output
DSI-1, verify status: connected, a nonzero CRTC, active=yes, and a plane assigned to that CRTC. Use the IDs reported by modetest, because they can vary by build.Restore Weston after testing a display mode.To test a different mode, follow Run DRM modetest, then Relaunch Weston before returning to Weston tests.
4. Check interface signals
Run the following command:
This prints the available DSI pixel-clock rates in Hz. Run the following command:
This lists the available DPU debug groups. Compare the rate with the active CRTC pixel clock in kHz. If no clock files are present, continue with the DRM and kernel checks.
5. Check current-boot kernel messages and live display events
Run the following command:To capture display events while reproducing the issue, run the following command:
This shows panel, DSI, and DRM messages from the current boot only. If it returns no lines, capture live data while reproducing the issue.
Reference output
This follows new Weston and kernel messages. Run it without
-k so the output includes compositor connector changes and output enablement. Reproduce the issue, then press Ctrl+C.Look for connector-state changes, EDID or mode detection, output enablement, and driver errors. Compare the relevant messages with the connector status and active DRM state.A successful boot binds the DSI controller and DPU. timeout, failed, or error messages point to the panel, DSI PHY, power, or clock path. If DRM is active with no matching error, check the panel cable and backlight routing, then compare the Weston output with the DRM state.6. Interpret the result
Verify the Weston service before checking the output layout.Run the following command:The expected result is
active. If the service is not active, Relaunch Weston before continuing.7. Check Weston and the output layout
Run the following command:
This shows the latest Weston messages from the current boot. Run the following command if Weston is active but the display is blank:
This lists the available Wayland socket names. Run the following command after replacing the placeholders:
Compare the Weston output with DRM state.This prints Weston output information. Find the selected display output and compare it with the DRM connector and CRTC state. If Weston is inactive, Relaunch Weston before continuing.