AMDGPU RAVEN screen freeze on switch from EFIFB to AMDGPUDRMFB
 

So I got a new Dell Inspiron 13 which has AMD's Vega 10 RAVEN graphics. I wanted to leave my success breadcrumbs for anybody coming after me and also solicit advice on where I'm stuck.

1. Initial boot, 14.2:

Booting at all requires the commandline "amdiommu=on ivrs_ioapic[4]=00:14.0 ivrs_ioapic[5]=00:00.2" This will boot and go to a black screen.

When I add "acpi_backlight=vendor nomodeset vga=normal", it boots to runlevel 3 fine, dropping EFIFB when the kernel takes over from ELILO. Obviously, no /dev/dri, no /sys/class/drm. X won't run, even on the VESA driver.

2. Updated to kernel 4.18, firmware from -current:

Since Linus was so kind as to release this today, I built Linux 4.18 and installed it. The first boot kvetched about bad firmware and not finding a BIOS, so I installed the kernel-firmware package from -current.

This worked fairly well. If I boot with the same command line as above (for those following along, that's "amdiommu=on ivrs_ioapic[4]=00:14.0 ivrs_ioapic[5]=00:00.2 acpi_backlight=vendor nomodeset vga=normal"), I get to runlevel 3, keeping the EFIFB the whole time (this was counterintuitive at first until I remembered the OS "thinks" the EFIFB is just a console). I can even run X on xf86-video-fbdev, with 1920x1080 resolution.

In theory, this should be fine and if I can't get any farther I'll still be happy with the laptop. However, I would like to get the actual AMDGPU FB working.

3. Updated libdrm

So now I've built the libdrm package from -current (2.4.93) and booted without nomodeset. This seems to boot well, except that when the screen message reaches

the display just freezes. It continues to boot, and restarts cleanly with the 3-finger salute.

Viewing the logs on the next boot with nomodeset, I can even see:

So, the DRM seems to think it's setting up a framebuffer, but it doesn't actually get it to the screen. I've tried this with and without acpi_backlight=vendor and it behaves exactly the same.

Am I missing something? Are there some other knobs I can tweak about getting the DRM to actually talk to the screen?

From when I did this, you also need libclc, libedit, llvm, and mesa from current.
At that point my AMD card did ok.

Successfully upgrading every package required on 14.2 to support the latest AMD graphics is a daunting prospect. I have attempted it myself, and eventually gave up. However, to be honest though, I gave up pretty quickly once I found out how easy it was to get things up and running on -current instead.

Unless you absolutely must run 14.2, I highly recommend starting with -current. With -current almost everything is already in place for AMD VEGA graphics, the only missing piece is a newer kernel series.

Thanks both. I ended up giving up on 14.2 and just going to -current. Add a more recent kernel and it Just Works (tm)