Fix regression introduced by commit cf7a63ef4e02 ("x86/tsc: Calibrate tsc only once") as it changed setup_arch() so that it now calls tsc_early_init() before acpi_boot_table_init() which is a necessary step, in the case of UV systems, to inform tsc_sanitize_first_cpu() that we're on a platform with async TSC resets as documented in commit 341102c3ef29 ("x86/tsc: Add option that TSC on Socket 0 being non-zero is valid") Fix by skipping tsc_early_init() on UV systems and let TSC initialization take place later in tsc_init(). Fixes: cf7a63ef4e02 ("x86/tsc: Calibrate tsc only once") Signed-off-by: Mike Travis Signed-off-by: Hedi Berriche Reviewed-by: Russ Anderson Reviewed-by: Dimitri Sivanich --- arch/x86/kernel/setup.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- linux.orig/arch/x86/kernel/setup.c +++ linux/arch/x86/kernel/setup.c @@ -117,6 +117,7 @@ #include #include #include +#include /* * max_low_pfn_mapped: highest direct mapped pfn under 4GB @@ -1015,7 +1016,10 @@ void __init setup_arch(char **cmdline_p) */ init_hypervisor_platform(); - tsc_early_init(); + /* UV TSC multi-chassis synchronization already set, don't change it */ + if (!is_early_uv_system()) + tsc_early_init(); + x86_init.resources.probe_roms(); /* after parse_early_param, so could debug it */ --