Hi John, On 2019/10/10 21:29, John Garry wrote: > This series is a backport of the ACPI PPTT 6.3 thread flag feature for > supporting arm64 systems. > > The background is that some arm64 implementations are broken, in that they > incorrectly advertise that a CPU is mutli-threaded, when it is not - the > HiSilicon Taishanv110 rev 2, aka tsv110, being an example. > > This leads to the system topology being incorrect. The reason being that > arm64 topology code uses a combination of ACPI PPTT (Processor Properties > Topology Table) and the system MPIDR (Multiprocessor Affinity Register) MT > bit to determine the topology. > > Until ACPI 6.3, the PPTT did not have any method to determine whether > a CPU was multi-threaded, so only the MT bit is used - hence the > broken topology for some systems. > > In ACPI 6.3, a PPTT thread flag was introduced, which - when supported - > would be used by the kernel to determine really if a CPU is multi-threaded > or not, so that we don't get incorrect topology. Thanks for doing this, and this patch set fix my CPU topology issue in 4.19 kernel with updated firmware. > > Note: I'm sending this as an RFC before sending to stable proper. I also > have a 5.2 and 5.3 backport which are almost the same, and only > significant change being that the ACPICA patch is not required. 5.2 stable was end of life, so only 4.19 and 5.3 are needed I think. Thanks Hanjun