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 Kernel Packages, which is subscribed to linux-firmware in 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) Status in amd: New Status in Linux: Incomplete Status in linux package in Ubuntu: Confirmed Status in linux-firmware package in Ubuntu: New Bug description: CPU: Ryzen 5 2500U VGA: Radeon 535 Notebook: Acer Aspire A315 This is a brand new notebook on the market with Ryzen 5/Radeon. The default kernel of Ubuntu(18.04) hangs at loading with message: tsc: Refined TSC clocksource calibration: 1996.250 MHz clocksource: tsc: mask: 0xffffffffffffffff max_cycles: (...), max_idle_ns: (...) Soft lockup Using pci=noacpi kernel parameter kernel loads without any problem but my notebook produces more heat than on Win10. If I know right Acer notebooks need ACPI to the correct power management. The same thing happens on mainline 4.17,4.18rc1-2. BIOS upgrade to the latest version: 1.08 hasn't helped This problem has been reported upstream: https://bugzilla.kernel.org/show_bug.cgi?id=200087 The latest correctly working kernel was 4.13.* but the heat problem was present with this too. To manage notifications about this bug go to: https://bugs.launchpad.net/amd/+bug/1776563/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
