https://bugzilla.kernel.org/show_bug.cgi?id=196117
Bug ID: 196117 Summary: amdgpu RC 480 (polaris) freeze after initramfs, before kernel load Product: Drivers Version: 2.5 Kernel Version: 4.11.6 Hardware: x86-64 OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Video(DRI - non Intel) Assignee: drivers_video-dri@kernel-bugs.osdl.org Reporter: paulkgerke@craftware.nl Regression: No
Created attachment 257069 --> https://bugzilla.kernel.org/attachment.cgi?id=257069&action=edit screen capture of the last kernel messages before system freeze
Hey all!
I recently swapped out my old Radeon HD7850 for a Radeon RX 480, that I only heard good things about on the Internet because of good kernel support. However, I ran into an issue: all kernels I tried hang after initramfs, but before the kernel actually boots. Here the symptoms:
I tried several kernels by now, the stock kernels that come with XUbuntu 16.04, and several upstream ones (e.g. 4.12.0). This will be about 4.11.6, which I now compiled myself.
- If I use "nomodeset" to boot the kernel, everything works fine, except for the graphics drivers which fails to initialize (amdgpu fails because of VGACON error).
- If I boot in with options "linux /vmlinuz... root=UUID=xxxx ro debug ignore_loglevel boot_delay=100"
PS: I also setup a serial link for debugging, but the crash seems to occur before the serial driver can start communicating, so no luck with that!
- I see "loading initial ramdisk..." ... booting takes 3 minutes until the crash with that delay... - I taped the whole thing to at least capture some sort of error. The attached screenshot is the best I got at the moment.
It says something about IOMMUv2 driver and... about it being not "avaialble on the system" (?) Is that my error? This is the last (half) frame before my screen turns black.
After this, my keyboard LEDs turn off, my mouse also turns off (it has fancy LEDs which light up if it is initialized) and my screen stays **on**, curiously. The machine is not responding after this.
At the moment I am stuck lacking good debugging tools. If somebody has an idea, I would be greatful. Until now, the only thing I can think of is digging into a fresh codebase - I bet graphics drivers are not really accessible though :-(
One last PS: The graphicscard I have works perfectly fine on Windows on the same system. It is clearly some software issue, I assume!