verdin-imx8mm_lt8912_overlay.dtbo is meant for toradex_5.4-2.3.x-imx
according device-tree-overlays-linux - displays, for:
Verdin iMX8M Mini >=6.1.0 (Linux kernel 5.15.x); verdin-imx8mm_dsi-to-hdmi_overlay.dtbo is the overlay to be used.
root@verdin-imx8mm-07222956:/sys/class/drm/card1-HDMI-A-1# dmesg | grep dsi
[ 0.267765] platform 32e10000.mipi_dsi: Fixing up cyclic dependency with 32e00000.lcdif
[ 1.538213] i2c 3-0048: Fixing up cyclic dependency with 32e10000.mipi_dsi
[ 6.438155] imx_sec_dsim_drv 32e10000.mipi_dsi: version number is 0x1060200
[ 6.662115] imx-drm 32c00000.bus:display-subsystem: bound 32e10000.mipi_dsi (ops imx_sec_dsim_ops [sec_mipi_dsim_imx])
root@verdin-imx8mm-07222956:/sys/class/drm/card1-HDMI-A-1# dmesg | grep drm
[ 4.177816] systemd[1]: Starting Load Kernel Module drm...
[ 4.421633] [drm] Initialized vivante 1.0.0 20170808 for 38000000.gpu on minor 0
[ 6.429110] imx-drm 32c00000.bus:display-subsystem: bound imx-lcdif-crtc.0 (ops lcdif_crtc_ops)
[ 6.662115] imx-drm 32c00000.bus:display-subsystem: bound 32e10000.mipi_dsi (ops imx_sec_dsim_ops [sec_mipi_dsim_imx])
[ 6.786065] [drm] Initialized imx-drm 1.0.0 20120507 for 32c00000.bus:display-subsystem on minor 1
[ 7.763276] imx-drm 32c00000.bus:display-subsystem: [drm] fb0: imx-drmdrmfb frame buffer device
root@verdin-imx8mm-07222956:~# cat /sys/kernel/debug/device_component/soc\@0\:bus\@32c00000\:display-subsystem
master name status
-------------------------------------------------------------
soc@0:bus@32c00000:display-subsystem bound
device name status
-------------------------------------------------------------
imx-lcdif-crtc.0 bound
32e10000.mipi_dsi bound
root@verdin-imx8mm-07222956:/sys/class/drm/card1-HDMI-A-1# ls
device dpms edid enabled modes power status subsystem uevent
root@verdin-imx8mm-07222956:/sys/class/drm/card1-HDMI-A-1# cat enabled
enabled
root@verdin-imx8mm-07222956:/sys/class/drm/card1-HDMI-A-1# cat status
connected
Everything seems fine, I can also see connected and disconnected when I unplug the HDMI cable. I’m using a PC monitor, I will try to find another HDMI device.
The setup works correctly with a regular HDMI TV and with Winstar WF101GTYFPLHT0# LCD-TFT Display 10.1" 1280x800 TFP40 Controller.
What is strange is that with Easy Installer the PC monitor works, but not with “regular” Toradex builds. So, the DSI to HDMI works correctly and the PC monitor is supported at hardware level. There must be some issue with the lt8912 driver or some configuration at system level. Unfortunately I don’t have time to investigate it, and having this PC monitor working is not part of the project.
Hi @josep.tx,
The referenced thread is very interesting, I’m not used to work with video in embedded systems, and long time ago it was just the fb
I don’t have time to dig the issue, and is not the target of my work. I have a HDMI device working, and it is just for a PoC, then we will use a different channel to connect the display.
But using the kernel parameters from u-boot video=HDMI-A-1:1920x1080@24 is one of the first thing that I’ve tried, checking the differences between Toradex EasyInstaller working setup and the latest reference multimedia image, but it didn’t worked for me. I’ve seen no difference.
