From: Petr Vandrovec <petr@xxxxxxxxxx> When processor is being hot-added to the system, acpi_map_lsapic invokes ACPI _MAT method to find APIC ID and flags, verifies that returned structure is indeed ACPI's local APIC structure, and that flags contain MADT_ENABLED bit. Then saves APIC ID, frees structure - and accesses structure when computing arguments for acpi_register_lapic call. Which sometime leads to acpi_register_lapic call being made with second argument zero, failing to bring processor online with error 'Unable to map lapic to logical cpu number'. As lapic->lapic_flags & ACPI_MADT_ENABLED was already confirmed to be non-zero few lines above, we can just pass unconditional ACPI_MADT_ENABLED to the acpi_register_lapic. Signed-off-by: Petr Vandrovec <petr@xxxxxxxxxx> Signed-off-by: Alok N Kataria <akataria@xxxxxxxxxx> Reviewed-by: Toshi Kani <toshi.kani@xxxxxx> Signed-off-by: Len Brown <len.brown@xxxxxxxxx> --- arch/x86/kernel/acpi/boot.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index ce664f3..bbcc2c3 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -642,6 +642,7 @@ static int __cpuinit _acpi_map_lsapic(acpi_handle handle, int *pcpu) kfree(buffer.pointer); buffer.length = ACPI_ALLOCATE_BUFFER; buffer.pointer = NULL; + lapic = NULL; if (!alloc_cpumask_var(&tmp_map, GFP_KERNEL)) goto out; @@ -650,7 +651,7 @@ static int __cpuinit _acpi_map_lsapic(acpi_handle handle, int *pcpu) goto free_tmp_map; cpumask_copy(tmp_map, cpu_present_mask); - acpi_register_lapic(physid, lapic->lapic_flags & ACPI_MADT_ENABLED); + acpi_register_lapic(physid, ACPI_MADT_ENABLED); /* * If mp_register_lapic successfully generates a new logical cpu -- 1.7.10.rc2.19.gfae9d -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
