On Mon, Jan 15, 2018 at 09:13:20PM +0000, Giles Orr via talk wrote:
The solution to this was hard to find but simpler than expected: add the 'noapic' option on the command line to the kernel at boot time, and magically everything is working fine. I did this after finding a reference to that on a page for the particular HP laptop - it was a problem a decade ago too. According to a RedHat page, " APIC is the replacement for the old PIC chip that, in the past, was embedded on motherboards and allowed the configuration of interrupts for peripherals like soundcards, IDE controllers, sharing/redirecting of interrupts. Disabling APIC removes the ability to make use of IRQ sharing or device IRQ remapping." Which is great and I can see that it might relate to fans, but ... I don't really get it.
Perhaps noapic actually causes acpi to get disabled (Perhaps acpi depends on apic) and certainly many many cases of broken acpi exists and acpi certainly could have influence on fan control. Does acpi=off work the same as noapic in this case? -- Len Sorensen