P33M

You're running an Ubuntu kernel that doesn't correspond to any release we've made for Raspberry Pi OS. Assuming you have a `pciex1-compat-pi5.dtbo` in your boot filesystem's `/overlays` directory, then add...

Resizeable BARs are an endpoint feature and no special handling by the RC is required. "Resizable BAR support" in an x86 BIOS merely ensures that the window for 64bit PCI...

Those patches are for a controller operating at the other end of a link, in response to a BAR resize configuration request. Does the Arc card get resized BARs if...

The card integrates PCI switches to separate the HDMI audio function from the GPU function. Not strictly necessary - you can have multiple functions on a single endpoint, but it's...

The address map for BCM2712 has 16GB allocated to each RC. An 8GB BAR should be supportable, but a 16GB one definitely won't fit, as the reservations for the other...

This appears to be a known bug - https://patchwork.kernel.org/project/linux-pci/patch/[email protected]/ I have applied that patch to https://github.com/raspberrypi/linux/pull/6653 which will shortly be available from `sudo rpi-update pulls/6653`. Additional userspace interaction is probably...

You have a GPU that has 16GB of VRAM, and that's not going to work - the total allocation for the GPU BARs exceeds the decode space in bcm2712. An...

xe.force_vram_bar_size is a likely-looking module parameter. Try 8192 (in cmdline.txt or alternatively when modprobing). I don't think you need to adjust resource2_resize but could be wrong.

After much faffing, I have a nearly-working resize. This is an Arc A380. cmdline.txt needs `xe.force_probe="56a1" i915.force_probe="!56a1"`. ``` root@cm5l:/home/pi# lspci -vs 0001:01:00.0 0001:01:00.0 PCI bridge: Intel Corporation Device 4fa0 (rev...

It's almost certainly a coherency issue - running `stress --vm 3` in the background made the driver load successfully. Auto-resize on probe also worked, but only after I pre-expanded the...