I'm running Ubuntu with kernel 6.14 on a dual-boot setup with Windows on an AMD platform featuring an NVIDIA RTX 5090 GPU with 32 GB VRAM. I've enabled both Secure Boot and TPM in my firmware settings, but doing so causes Linux to fail to boot. The kernel logs are flooded with PCIe BAR allocation errors that prevent the NVIDIA driver from initializing properly. However, if I disable TPM, Linux boots without any issues. I've already tried modifying the grub configuration with 'iommu=pt pci=realloc' and booting with different framebuffer settings, but without TPM enabled, I'd rather keep it on for Windows. Does anyone have ideas on how to resolve this? I've been troubleshooting for a couple of days now, and I'm relatively new to Linux. Also, I'm sure the NVIDIA drivers are correctly signed and registered with mokutil since they attempt to load. Could the errors I'm seeing be due to something else?
4 Answers
This seems like a known issue with the RTX 50 series and Linux. The errors you're seeing happen when Secure Boot and TPM are enabled because they can mess with memory allocation during boot. The NVIDIA driver relies on specific memory assignments, and if it can't get that large contiguous block of memory due to firmware restrictions, it won't initialize. Try checking for firmware updates or maybe giving a newer kernel a shot.
You might want to switch to a more modern distribution. That GPU is pretty new, and some older systems might struggle with drivers. Also, sbctl is usually a better tool than mokutil for managing Secure Boot.
Honestly, maybe just turn off all that security nonsense. TPM and Secure Boot can be more trouble than they're worth. It feels like they’re just meant to frustrate you and make you buy new hardware if something goes wrong!
You might want to check how you've configured Secure Boot on your Linux side. When I used Nobara and Cachy, I registered the Microsoft keys with sbctl to make Secure Boot work smoothly. Maybe it could help you too?
What you suggested seems fine, but just in case, I’ve heard that Resizable BAR might be causing some issues with specific setups. A friend with that same GPU mentioned performance drops in some games with it enabled.