Hello Mike, On Sun, Jan 03, 2021 at 03:47:53PM +0200, Mike Rapoport wrote: > Thanks for the logs, it seems that implicitly adding reserved regions to > memblock.memory wasn't that bright idea :) Would it be possible to somehow clean up the hack then? The only difference between the clean solution and the hack is that the hack intended to achieved the exact same, but without adding the reserved regions to memblock.memory. The comment on that problematic area says the reserved area cannot be used for DMA because of some unexplained hw issue, and that doing so prevents booting, but since the area got reserved, even with the clean solution, it shouldn't have never been used for DMA? So I can only imagine that the physical memory region is way more problematic than just for DMA. It sounds like that anything that touches it, including the CPU, will hang the system, not just DMA. It sounds somewhat similar to the other e820 direct mapping issue on x86? If you want to test the hack on the arm board to check if it boots you can use the below commit: https://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git/commit/?id=c3ea2633015104ce0df33dcddbc36f57de1392bc Thanks, Andrea
