topic Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem in i.MX Processors

iMX8QM-MEK HDMI Output 2400x900@60 Problem

nevozade — Thu, 28 Jul 2022 13:40:08 GMT

Hello,

I have built a yocto distro for fsl-imx-xwayland and iMX8QM-MEK machine with v5.4.70 kernel version as below.

I wish to output from 3 panels: 2 of them are LVDS outputs and 1 of them is HDMI output, all of them at the same time.

2 x panels have physical resolution 1920x720@60 and connected to iMX8QM-MEK eboard via LVDS lines with dual mode as represented figure below.

1 x panel has physical resolution 2400x900@60 and connected to iMX8QM-MEK eboard via HDMI port.

* When I use the attached DTS file imx8qm-mek-hdmi.dts.txt, 2400x900@60 panel works fine which is connected to HDMI port. But there are no outputs on LVDS panels.

* When I use the attached DTS files imx8qm-mek-jdi-wuxga-lvds1-panel.dts.txt and imx8qm-mek-jdi-wuxga-lvds1-panel.dtsi, both 1920x720 LVDS panels work fine but there is no output on 2400x900@60 panel which is connected to HDMI port. If I unplug the HDMI connection from 2400x900@60 panel and plug a standard 1280x720@60 PC monitor via HDMI port, there is an output (works fine) on that PC monitor.

On the other hand, I have set the u-boot bootargs variable to adjust the HDMI output setting as below.

bootargs=root=/dev/mmcblk0p1 rootwait rw video=mxcdi0fb:RGB24,2400x900M@60,hdmi video=mxcdi1fb:RGB666,XGA,di0_primary ldb=di1 ip=none

How can I output from all of the panels (2 x LVDS 1920x720@60 and 1 x HDMI 2400x900@60) at the same time. What should be the rootcause of that problem ?

Note: DTS files are attached.

Regards,

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

nevozade — Fri, 05 Aug 2022 12:08:39 GMT

@Oliver Brown

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

nevozade — Fri, 05 Aug 2022 12:18:36 GMT

@igorpadykov

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

OliverB — Fri, 05 Aug 2022 18:17:46 GMT

I made the patch below for imx8qm-mek-jdi-wuxga-lvds1-panel-rpmsg.dts and I can get the LVDS panel on LVDS1 and HDMI working together.

$ git diff
diff --git a/arch/arm64/boot/dts/freescale/imx8qm-mek-jdi-wuxga-lvds1-panel-rpmsg.dts b/arch/arm64/boot/dts/freescale/imx8qm-mek-jdi-wuxga-lvds1-panel-rpmsg.dts
index b57423235fc7..37b0ccfe5d4f 100644
--- a/arch/arm64/boot/dts/freescale/imx8qm-mek-jdi-wuxga-lvds1-panel-rpmsg.dts
+++ b/arch/arm64/boot/dts/freescale/imx8qm-mek-jdi-wuxga-lvds1-panel-rpmsg.dts
@@ -4,5 +4,5 @@
* Copyright 2020 NXP
*/

-#include "imx8qm-mek-rpmsg.dts"
+#include "imx8qm-mek-hdmi.dts"
#include "imx8qm-mek-jdi-wuxga-lvds1-panel.dtsi"

The problem getting LVDS0 and HDMI working is that in our default configuration display controller 0 is set to be used by HDMI only. So both display pipes are configured to be used by the HDMI. It should be possible to split the display controller to use one pipe for HDMI and one pipe for LVDS. I'll investigate what changes are required.

Is it possible to MIPI DSI1 for your use case? The default imx8qm-mek-default.dts supports HDMI, LVDS1 and MIPI DSI1 (LVDS0 and MIPI DSI0 are disabled).

Regards,

Oliver

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

OliverB — Fri, 05 Aug 2022 22:07:56 GMT

I was able to get HDMI working with LVDS0 and LVDS1. The HDMI display needs to be limited to 2560 pixels or less and less than 300MHz pixel clock. Otherwise LVDS0 will not have a display. In this patch I also had to disable hdmi audio due to a probe conflict. Let me know if this is working for you.

Regards,

Oliver

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

nevozade — Mon, 08 Aug 2022 05:23:37 GMT

Hello @OliverB ,

Firstly, thanks for your quick reply, this issue is so urgent and important to me.

I have applied your patch and 1 HDMI and 2 LVDS work now. However still I have a problem. Now just I can get 1920x1080 resolution from HDMI; but I need 2400x900 like FHD+. Without your patch if I use imx8qm-mek-hdmi.dtb, HDMI (2400x900) works; but not any LVDS. If I use imx8qm-mek-jdi-wuxga-lvds1-panel.dtb, just 2 LVDS work, no HDMI. When I apply your patch 2 LVDS OK; just HDMI (1920x1080) OK, not 2400x900. What is the reason of not working 2400x900 with LVDSs and how can I solve this problem? Or is this case possible?

Best regards.

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

OliverB — Mon, 08 Aug 2022 15:22:02 GMT

Hi Nevozade,

I'm not sure why it is not working for your resolution. Can you you provide the EDID from you 2400x900 monitor? You can just provide the output of "modtest" from when your monitor is working in HDMI mode. I'll have to set this mode on my analyzer and see what is causing the problem. Both the display controller driver and HDMI Driver should allow this mode in a single display pipe. It's possible "1920" is hardcoded somewhere in the drivers.

Regards,

Oliver

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

nevozade — Mon, 08 Aug 2022 16:24:32 GMT

Hi @OliverB ,

Actually, we analyzed the EDID of our monitor before and we saw that 2400x900. According to your request, I am sending you the edid file for you to analyze and find the problem. I am asking for your support in this matter. (I attach the file as .zip because the .bin extension has failed to upload)

Best Regards,

Nevzat

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

OliverB — Tue, 09 Aug 2022 14:56:24 GMT

I verified that HDMI 2400x900 and two LVDS 1920x1200 can work with your edid and 0001-arm64-boot-dts-freescale-Add-configuration-for-two-L.patch. I did not need any uboot changes or weston.ini changes. I also previously verified that 2560 width can work, this would be the upper limit of the width for a single display pipe.

Also the settings below are not for iMX8QM and should not be used:

video=mxcdi0fb:RGB24,2400x900M@60,hdmi video=mxcdi1fb:RGB666,XGA,di0_primary ldb=di1

These are for iMX6DQ with IPUv3.

To force a DRM mode the form should be

video=HDMI-A-1:2400x900-32@60

My patch supports the dual-channel 1920x1200 NXP display panel, so some change would be needed to get change the panel and disable dual channel mode.

Regards,

Oliver

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

nevozade — Tue, 09 Aug 2022 15:07:36 GMT

Hello @OliverB

Even I use your patch, HDMI 2400x900 and LVDS not working for me. If I disabled lvds-channel@0 HDMI works. If I make "okay" lvds-channel@0 LVDS works. It seems when HDMI starts to work LVDS disabled automatically. You can my final dts as attached. What is the reason of this issue?

Best regards.

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

nevozade — Tue, 09 Aug 2022 16:03:02 GMT

Hi @OliverB,

Although I think I'm doing it right, just in case could you zip and share the freescale folder (including dts and dtsis) in build/tmp/work-shared/imx8qmmek/kernel-source/arch/arm64/boot/dts/ path with me? I want to make sure I'm doing the same thing you did before I move forward.

Thanks.

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

OliverB — Tue, 09 Aug 2022 16:05:54 GMT

Can you provide the full log from powerup to the linux prompt?

Regards,

Oliver

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

nevozade — Tue, 09 Aug 2022 16:13:00 GMT

Hi @OliverB ,

The case that 2 LVDS panels work together, but HDMI (2400x900) does not work -> lvds.log and imx8qm-mek-jdi-wuxga-lvds1-panel-LVDS.dtsi
The case that HDMI (2400x900) works, but no display on LVDS panels -> hdmi.log and imx8qm-mek-jdi-wuxga-lvds1-panel-HDMI.dtsi

All specified files exist in the attached zip file.

Best Regards,

Nevzat.

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

OliverB — Tue, 09 Aug 2022 17:13:57 GMT

Can you try this file? The LVDS nodes were disabled.

All three display are working with this file included as follows:

--- a/arch/arm64/boot/dts/freescale/imx8qm-mek-jdi-wuxga-lvds1-panel.dts
+++ b/arch/arm64/boot/dts/freescale/imx8qm-mek-jdi-wuxga-lvds1-panel.dts
@@ -5,4 +5,4 @@
*/

#include "imx8qm-mek.dts"
-#include "imx8qm-mek-jdi-wuxga-lvds1-panel.dtsi"
+#include "imx8qm-mek-jdi-wuxga-lvds1-panel-HDMI-fixed.dtsi"

Regards,

Oliver

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

OliverB — Tue, 09 Aug 2022 17:29:36 GMT

Here are the device tree files. I hope they helps.

Regards,

Oliver

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

nevozade — Wed, 10 Aug 2022 06:53:38 GMT

Hi @OliverB ,

Sorry, due to local time difference, I have just tried your suggestions.

Firstly, I changed imx8qm-mek-jdi-wuxga-lvds1-panel.dts file as you said (changed include file) with your attached dtsi file. Then, I make dtb files and write to SD card. However, although I set different dtb files on booting many times, there is no display at the same time LVDS and HDMI panels. Even the HDMI with imx8qm-mek-hdmi.dtb that worked with us did not work with your dtb. Only way to get view on HDMI is disabling lvds-channel0, which gives HDMI output but closes LVDS panels.

Secondly, I copy your freescale folder by overwriting mine. Then, write them into SD card but there is no change with the display issue. I set different fdt_file on booting such as imx8qm-mek-jdi-wuxga-panel.dtb, imx8qm-mek-hdmi.dtb, and imx8qm-mek-jdi-wuxga-lvds0-lvds1-hdmi.dtb , nothing changes. The HDMI monitor that you have is acting different from ours in my opinion. Any other suggestion?

Best Regards,

Nevzat

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

tuncayyldrm — Wed, 10 Aug 2022 15:10:32 GMT

We cannot meet the criteria I show in the figure. What do I need to do to provide the resolutions in the options given here?

Even though I took 2 LVDS and HDMI together, it was not possible to reach the resolutions I wanted and shown in the figure.

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

OliverB — Wed, 10 Aug 2022 15:24:17 GMT

Can you provide the source for the slide "Seeris Display Output Capabilities"?

Can you also provide video mode definitions and/or EDIDs for the displays that you tried?

The current driver has a single display pipe width limit of 2560 pixels. This means that 2 2560 width displays are possible on a single display pipe. Which also means that up to 3 or 4 2560 width displays are possible. Or one larger display up to 5120 pixel width and two displays up to 2560 width.

Regards,

Oliver

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

hkaracali — Wed, 10 Aug 2022 16:33:34 GMT

Hello @OliverB ,

We are trying to get at least 2 panels (one of them HDMI, one of them LVDS). Now 1 LVDS(1920x720) and 1 HDMI(1920x720) work fine. However when we changed HDMI with 2400x900 monitor, there is no image in the monitor. You can see reference slide as attached. Could you please give a way to find root cause of this issue?

Best regards.

Re: iMX8QM-MEK HDMI Output 2400x900@60 Problem

nevozade — Wed, 10 Aug 2022 17:39:45 GMT

Hi @OliverB ,

We had already shared the EDID of our panel you before as zipped file.

Thanks.