# Upgrading to Bookworm CM4 **URL:** \ **Category:** uConsole\ **Tags:** tinkering\ **Created:** [December 4, 2023, 7:15pm UTC](https://forum.clockworkpi.com/t/upgrading-to-bookworm-cm4/11831 "2023-12-04T19:15:32Z")\ **Posts on this page:** 5\ **Page:** 2
**Author:** ![fido\_node](https://avatars.discourse-cdn.com/v4/letter/f/4da419/32.png) [@fido\_node](https://forum.clockworkpi.com/u/fido_node)\ **Post date:** [January 28, 2024, 9:29pm UTC](https://forum.clockworkpi.com/t/upgrading-to-bookworm-cm4/11831/21 "2024-01-28T21:29:34Z")
You can hope for it, but don’t expect it. There is a [major bug](https://github.com/raspberrypi/linux/issues/4323) in fresh kernel version which affects interface between cm4 and display panel. Most of the times panel works, but sometimes it just black and you need to reboot or push it programmatically couple of times. I settle down with [this patchset](https://github.com/PotatoMania/uconsole-cm3). I’ve slightly modified it to fit my needs and armbian build requirements. I’ll try to create and instruction and repo with neede files to build your own armbian image with a flavor of your choice, but still no promises. Here is a pic to tease other tinkerers 😉 ![GE9QDTSXMAA5Bcq](https://canada1.discourse-cdn.com/flex029/uploads/clockworkpi/original/2X/6/633959e00826fd5ac75c7d5b4bb7806a411e55fb.jpeg) ---
**Author:** ![Nick\_Stevens](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/nick_stevens/32/8839_2.png) [@Nick\_Stevens](https://forum.clockworkpi.com/u/Nick_Stevens)\ **Post date:** [January 29, 2024, 6:53am UTC](https://forum.clockworkpi.com/t/upgrading-to-bookworm-cm4/11831/22 "2024-01-29T06:53:16Z")
Thank you for the clarification. ---
**Author:** ![JamesBelchamber](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/jamesbelchamber/32/9060_2.png) [@JamesBelchamber](https://forum.clockworkpi.com/u/JamesBelchamber)\ **Post date:** [February 20, 2024, 7:54am UTC](https://forum.clockworkpi.com/t/upgrading-to-bookworm-cm4/11831/23 "2024-02-20T07:54:54Z")
The display controller is supported as of Linux 6.2, so it may make sense to move directly to Trixie (6.6) for testing. [https://lore.kernel.org/all/20220908135940.299324-4-jagan@edgeble.ai/](https://lore.kernel.org/all/20220908135940.299324-4-jagan@edgeble.ai/) Joseph tested it and it didn’t work (😂) but since there’s code now in the kernel that supports it you might find it more fruitful to debug that than try to get the old patch working: > **[Joseph Hewitt (@jhewitt.net)](https://bsky.app/profile/jhewitt.net/post/3klpctopsnd2u)** > > Unfortunately this driver isn't performing any better. On both drivers, I get DSI transfer kernel errors and the panel does not initialize properly (or at all). > > I was able to force it to work sometimes on the Clockwork driver by putting the init in... I don’t have my uConsole yet but once I do I’d be happy to work on it too (my hope is to get Fedora running on it). ---
**Author:** ![PotatoMania](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/potatomania/32/8072_2.png) [@PotatoMania](https://forum.clockworkpi.com/u/PotatoMania)\ **Post date:** [February 21, 2024, 4:37am UTC](https://forum.clockworkpi.com/t/upgrading-to-bookworm-cm4/11831/24 "2024-02-21T04:37:29Z")
When I was tinkering the panel driver for CM3, I tried mainline kernel(and some major versions from 5.15 to 6.6) and the corresponding driver, but never succeeded(and I was asking for help in this forum). The panel’s controller wasn’t even revealed! Then I switched to RPi’s downstream and found that `ctx->panel.prepare_upstream_first = true;` is required which was proposed and implemented by developers at RPi. I refer the new driver code when I was writing a customized one for uConsole’s panel. My latest driver patch for this panel is working and I think it’s clean, and is likely to fit RPi’s 6.6 branch. I won’t recommend to use mainline kernel on RPi unless it has to be mainline. The panel might be supported by newer mainline kernel, but the DSI controller on RPi may be not well supported. ---
**Author:** ![dotsony](https://avatars.discourse-cdn.com/v4/letter/d/90ced4/32.png) [@dotsony](https://forum.clockworkpi.com/u/dotsony)\ **Post date:** [February 23, 2024, 11:25pm UTC](https://forum.clockworkpi.com/t/upgrading-to-bookworm-cm4/11831/25 "2024-02-23T23:25:14Z")
If anyone wants help with testing, I’m available. Not on BlueSky, but I am here. [Previous page](https://forum.clockworkpi.com/t/upgrading-to-bookworm-cm4/11831.md?page=1)