Display system on IMx8mn with mainline kernel 6.13

[blessyAbraham]

Hi, 

I am trying to bring-up my display panel on a imx8mn hardware with the mainline kernel version 6.13. 

I have enabled the following drivers,

IMX_IPUV3_CORE=m
DRM=m
DRM_IMX=m
DRM_ETNAVIV=m
DRM_ETNAVIV_THERMAL=m
DRM_IMX_LCDIF=m

DRM_SAMSUNG_DSIM=m

Even though I am able to see the DSI devices enumerated in the drm filesystem, Running a modetest with imx-lcdif gives me a kernel crash. But the backlight has turned on. 

If i enable DRM_IMX_MXSFB, I do not see a kernel crash. But no image comes on the display. The backlight turns on. 

Is there other dependencies for IMX8mn, to have the display working on a mainline linux kernel 6.13?

[blessyAbraham]

Thankyou for your reply. 

I got the display up. I was giving a wrong clock frequency for the samsung DSIM in device tree. 

Verified the imx8mn-evk.dtsi and added the same.

[Bio_TICFSL]

Hello,

For your i.MX8M Nano display issue with mainline kernel 6.13, there are several considerations to resolve the problem.

Your kernel configuration seems to have the necessary drivers enabled:
- IMX_IPUV3_CORE=m
- DRM=m
- DRM_IMX=m
- DRM_ETNAVIV=m
- DRM_ETNAVIV_THERMAL=m
- DRM_IMX_LCDIF=m
- DRM_SAMSUNG_DSIM=m

The fact that the backlight turns on indicates partial initialization is working. The kernel crash with imx-lcdif but not with DRM_IMX_MXSFB suggests a compatibility issue.

For i.MX8M Nano display functionality in mainline kernel 6.13, you need to ensure:

1. The correct panel driver is properly integrated with the MIPI DSI controller
2. The device tree properly defines the display panel and its connection to the MIPI DSI controller
3. Any necessary bridge drivers are correctly implemented

To debug the issue:
1. Enable DRM debug mode: `echo 0x1ff > /sys/module/drm/parameters/debug`
2. Check kernel logs for detailed error messages from the display drivers
3. Verify your panel driver matches your specific display panel specifications

For i.MX8M Nano, you may need to customize the display driver initialization sequence based on your specific panel. The mainline implementation might require additional configuration compared to NXP's BSP.

If using a custom display panel, you'll need to modify the panel driver to match your specific display requirements, particularly the initialization commands and display timing parameters.

Regards