Hi AaronMa, thanks for the response. I tried it but it didn't work. I think iommu problem is not the main reason of the kernel hang. Otherwise it can be disabled in BIOS and there is no change.
The main reason is: https://bugzilla.kernel.org/attachment.cgi?id=276587 like you can se on this picture is that IOAPIC[4] and IOAPIC[5] are not in the invrs table so we should search the correct pci controllers using lspci and give them to the kernel. In this way: LINUX_DEFAULT="quiet splash ivrs_ioapic[4]=00:14.0 ivrs_ioapic[5]=00:00.2" Kernel can be started even with noapic but two sensors will be missing and the advanced touchpad functions will not work. This is the reason of CONFIG_VGA_SWITCHEROO=n compile time kernel parameter. There is an another problem: this notebook has two GPUs and amdgpu (or the kernel, I don't know) can not handle this correctly so gpu switching has to be disabled -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1776563 Title: Acer Aspire A315 ACPI failure on Ubuntu 18.04, kernel hangs, can't load, kernel freeze (AMD Ryzen 5/Radeon/Raven) To manage notifications about this bug go to: https://bugs.launchpad.net/amd/+bug/1776563/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
