DPU LCDIF not working on i.MX 8X MEK

[philippe_schenk]

Dear Sir or Madam

We still have some issues with LCDIF, which lead me to try it on the i.MX 8X MEK board. However I found that the device-tree for driving LCDIF with the DPU (imx8qxp-mek-dpu-lcdif.dts) is not working on your hardware.

I tried with the binary of following releases. I only switched device-tree in U-Boot with command

setenv fdt_file imx8qxp-mek-dpu-lcdif.dtb

• Linux 5.4.70_2.3.0​
  • While booting it misses some power-supplys and its stuck in boot-loop (never finishes booting)
• Linux 5.10.72_2.2.0
  • Same issue as with 5.4 (While booting it misses some power-supplys and its stuck in boot-loop, never finishes booting)
• Linux 5.15.5_1.0..0
  • Here it is booting. However, "modetest" does not show any indication of a display running.

Q1: Could you tell me order numbers for a compatible LCDIF display for i.MX 8X MEK with Baseboard?

Q2: How do I make the device-tree imx8qxp-mek-dpu-lcdif.dtb work on i.MX 8X MEK?

Note: I already tried to solve some of the issues we have in the past but eventually gave up. The thread may be found here: https://community.nxp.com/t5/i-MX-Processors/Parallel-RGB-LCDIF-issue-on-i-MX-8X/m-p/1357256#M181717

Best Regards,
Philippe Schenker (Toradex)

Cc: @bernhardfink

[Zhiming_Liu]

Hi @philippe_schenk 

Please provide two boot logs that meets the following conditions：

1.While booting it misses some power-supplys and its stuck in boot-loop (never finishes booting)

2.Boot log without panel.

[philippe_schenk]

Hi Qmiller,

I kindly ask you to reproduce it on your side so we have an independent way how it was reproduced. And since I did no changes at all (just swapping to the panel-devicetree) I am very confident this should be easy on your side.

Thanks and Best Regards,
Philippe

[Zhiming_Liu]

Hello @philippe_schenk ,

Our team doesn't have such motherboard and panel.

So this is our test result based on MEK without  panel:

1.modetest can't read CRTC information

2. stuck in boot-loop never happened

Application Team need log about this issue[stuck in boot-loop].If they can't handle this, the RD team will provide a workaround for this.

Best Regards

Zhiming

[philippe_schenk]

HI Qmiller,

I'm sorry I was not able to reproduce the issue in an acceptable time-frame. Our focus also switched away from this product - however the issue still persists without a solution. I was able to make it work on newest 5.15.52-2.1.0 release so I guess we could continue our measurements on there if desired by our internal team.

Anyway long story short we can close this. Thanks for your support!

Best Regards,
Philippe

[karina_valencia]

@Zhiming_Liu please help to continue with the follow-up here.

[Zhiming_Liu]

Hi @karina_valencia 

I have created internal case and need get reply from R&D

[brandon_shibley]

This issue remains open and we are still seeking clarification about using imx8qxp-mek-dpu-lcdif.dts

Please additionally answer these two questions:

1. Can you confirm that LCDIF is verified & supported on the i.MX 8X?

2. Can you share more specifics about the test & setup used to verify it with the MEK?

[Zhiming_Liu]

Hi @brandon_shibley 

The modetest can work under L5.15.32_2.2.0 on QXPC0 MEK.

Please see my attached log.

[brandon_shibley]

The issue persists on 5.4. We're in the process of bringing up 5.15 and will report back after we test it there.

[philippe_schenk]

@Zhiming_Liuping, any news why your lcd device-trees do not work on newest NXP release?

[Zhiming_Liu]

Can you share the reversion of your MEK board?

Have you change the dts node in arch/arm64/boot/dts/freescale/imx8x-mek-dpu-lcdif.dtsi?

[philippe_schenk]

Hi Qmiller

Thank you for your reply.

Yes, I really without adjusting anything just switched over to the stated device tree.

I used a MEK that has the following Stickers on it (which I hope enables you to identify the version):

• VV19460087
• SCH-29683 REV D4
• 700-29683 REV C2
• TDA7256
• MAC ID: 00:04:9F:06:6B:56
• Si C0

To be clear: I didn't yet come to our core question (which is technically non-trivial). We would like to debug further on NXP HW/SW, to see if we can reproduce the issue we have. However it does not work at all, without any changes so we need some advice how to proceed.

[Zhiming_Liu]

The default panel in i.MX 8X MEK is "sii,43wvf1g".

How do you connect the lcd panel to i.MX8X MEK board? Do you use special baseboard?

[philippe_schenk]

I know what compatible of panel do you use in the device tree. I kindly ask you to answer my questions. I happily repeat them:

Q1: Could you tell me order numbers for a compatible LCDIF display for i.MX 8X MEK with Baseboard?

Q2: How do I make the device-tree imx8qxp-mek-dpu-lcdif.dtb work on i.MX 8X MEK?

I do not connect any lcd panel to the i.MX8X MEK so far, we can measure the core-issue I'm talking about with the scope but it would be of course easier if we could attach the Seiko panel to the MEK. For this reason I asked Q1.

But we can not even measure the signals since imx8qxp-mek-dpu-lcdif.dtb is not working, this was the reason I asked Q2.

If you don't know the answers to my questions I sincerely ask to forward them internally.

Thanks and Best Regards
Philippe

[Zhiming_Liu]

Hi @philippe_schenk 

We use this panel: 

https://datasheet.octopart.com/RA169-Seiko-datasheet-142521498.pdf

Normally, set dtb in uboot will let lcdif work.Which signal did you measure?

Regards

Zhiming

[philippe_schenk]

Thanks for the link to the actual part. This at least answers a small portion of Q1. But how do you connect it to J20 (Audio Slot 1) PCIe x8 connector on the Baseboard?

Normally, set dtb in uboot will let lcdif work.Which signal did you measure?

Normally yes, however as you can read in my initial post it does not work on releases 5.4 5.10 and 5.15. I would like to ask you to reproduce it on your end and trigger to get those dtbs for lcd interface working.

Best Regards,
Philippe

[marcelziswiler]

Dear NXP, we are still waiting on an answer here. Thanks!