DPI mode with May 15th eeprom

Open
#1,397 23 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
linux, raspberry-pi

Research direction

Reproduce the blank DPI LCD on an RPi 4 using the May 15 2020 bootloader and compare it with the April bootloader, keeping the same SD image. Check the reported kernel versions, 4.19.97-v7l+ and 5.4; done means the DPI display initializes correctly with the newer bootloader.

Written by the indexing model from the issue text.

Description

On an RPi 4, DPI LCD will not display anything after updating to May 15th bootloader. The Display is active, hsync, vsync, dotclock and data enable are all active, but the display is blank.

bootloader_version info:
May 15 2020 11:05:52
version 23a9f59b85f5a81bb2eec455e064ef9905216322 (release)
timestamp 1589537152

Using the same SD image with the stable bootloader from April DPI LCD starts up correctly.
Using the same SD image on a second RPi4 with the May 15 bootloader I get just a blank screen.
After reverting that RPi4 back to the April bootloader the problem goes away.

Note this image is running kernel: Linux retropie 4.19.97-v7l+ #1294 SMP Thu Jan 30 13:21:14 GMT 2020 armv7l GNU/Linux.

I also tried with an image using kernel 5.4. Same problem.

Note I was testing the beta bootloader so I could setup a USB SSD when I found this problem, then I back tracked to my previous image which still had the problem, and then I tried my previous image with another RPi4 with the stable eeprom bootloader.

Hoping this is something stupid on my part.

Dominant language
No language data
Stars
5.6k
Forks
1.7k
PR merge metrics
No merged PRs in 30d

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from raspberrypi/firmware

All issues in raspberrypi/firmware

Similar issues

More Embedded & IoT issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.