Dell Latitude 5290: screen resolution issue with USB-c output

[pulleyluke]

Hey everyone, Ive got a hackintosh machine that I've made that runs great, its a Dell Latitude 5290, Core i3 - 8130U, Ive managed to get everything working on the latest opencore 1.0.1 and previously was running Sonoma and have updated to Sequoia with no problems, except one!

At work I have the laptop plugged into a HP USB C Dock G5, which has a 1440p monitor, mouse and keyboard all connected, everything seems to work, Mac OS identify's the monitor correctly and even has the correct connection type, my issue is that I can only run the monitor at 1080p, its picked up correctly as a 1440p monitor but if the resolution is set any higher than 1080p the monitor remains blank and says there is no input, but setting the monitor to 1080p works fine.

This problem was happening on Sonoma as well, also when I connect the dock to a real mac everything works perfectly at 1440p, also when I boot Linux or Windows on the Dell the monitor works fine as well.

Also I should note I've also been successfully building an EFI for a Dell Latitude 7390, and it has the exact same issue as my 5290.

 

I should also add that plugging the monitor into the laptop's HDMI port allows it to work completely fine at 1440p, but if I use a usb-c to hdmi or usb-c to displayport I get the same issue as I get when using the docking station.

 

Any help would be really appreciated thanks!

[Jake Lo]

Post your EFI

Might need to patch the pre-allocated DVMT, see here

Dell don't have the option in the BIOS to set it conveniently like HP

[Hervé]

Seems more to be an issue with the USB-c output. Post an IOReg with Dock plugged in and screen set to 1080p + screen set to 1440p.

[pulleyluke]

Sorry for the late response, my EFI is posted here:
https://github.com/lukeshondas/Dell-Latitude-5290-Opencore/tree/main

and here are the IOreg screenshots of anything that might be helpful.

 

I think the cause might be down to VRAM, so what Jake said might be worth trying.

Sorry, Just Realised i forgot to name the screenshots.

The first one is the dock with 1440p monitor running at 1080p

Second is the 1440p running at 1440p out of the laptops HDMI port.

and last is the 1440p monitor "running" at 1440p via the dock.

[WhenMusicAttacks]

for 8th gen it should be:

setup_var.efi 0xA10 0x02

but always better to test first (or get ready to disconnect cmos battery if fails)

another guide is here: https://github.com/dreamwhite/bios-extraction-guide/tree/master/Dell

[pulleyluke]

Okay thank you! Ill give it a shot, how much vram would you recommend? I've got 32GB of Ram on the laptop

[WhenMusicAttacks]

i think only 64mb makes any difference, higher value do nothing, but i might be wrong here

that wass for sure what i needed to get 2k 144hz on my 7400 before

[pulleyluke]

After following the guide made by Jake Lo the laptop now has 64MB of DVMT, and can now boot without the need for the framebuffer patch, but sadly my monitor issue isnt fixed. Same as before

[pulleyluke]

Have now tried a HP dock, Thinkpad dock and Dell Dock, all with the same issue, though sometimes the monitor would show some garbled image as you can see

[Jake Lo]

post you Config file