I experienced this problem on a machine with the following hardware: CPU: AMD FX-8350 (8) @ 4.000GHz GPU: AMD ATI Radeon R7 370 / R9 270/370 OEM
After bisecting from the 5.10.149 sources, I found that the commit responsible for this bug was 867b2b2b6802fb3995a0065fc39e0e7e20d8004d, corresponding to upstream commit 66f99628eb24409cb8feb5061f78283c8b65f820. This commit was reverted already on the 5.10 tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-5.10.y&id=357db159e965efa6a0b7b6f9efa1c34bf876db2d Indeed, vanilla Linux 5.10.153, which contains this revert and which is the currently latest release in the 5.10 branch, seems to boot properly with the amdgpu driver. The Debian package linux-image-5.10.0-19-amd64 is built from sources corresponding to the upstream release 5.10.149, which did NOT contain the fix. This seems to explain why many people with AMD GPUs, myself included, were experiencing problems during boot. Since this problem seems to have been fixed upstream, I don’t think there is anything to do on the Debian side... except of course packaging the next linux-image package with a Linux source tree containing these fixes. I’m happy to provide more information about this if anyone deems it necessary. Best regards. -- Cosimo Agati
