Enhance ACPI CPU hotplug driver to print clear error message and bail out early if BIOS returns wrong value in ACPI MADT table or _MAT method. Otherwise it will add the CPU device even if failed to get APIC ID and fails any operations against sysfs interface: /sys/devices/system/cpu/cpux/online Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx> --- drivers/acpi/acpi_processor.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 3c1d6b0..6ce71b0 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -212,7 +212,7 @@ static int acpi_processor_get_info(struct acpi_device *device) union acpi_object object = { 0 }; struct acpi_buffer buffer = { sizeof(union acpi_object), &object }; struct acpi_processor *pr = acpi_driver_data(device); - int cpu_index, device_declaration = 0; + int apic_id, cpu_index, device_declaration = 0; acpi_status status = AE_OK; static int cpu0_initialized; unsigned long long value; @@ -258,18 +258,21 @@ static int acpi_processor_get_info(struct acpi_device *device) device_declaration = 1; pr->acpi_id = value; } - pr->apic_id = acpi_get_apicid(pr->handle, device_declaration, - pr->acpi_id); - cpu_index = acpi_map_cpuid(pr->apic_id, pr->acpi_id); - /* Handle UP system running SMP kernel, with no LAPIC in MADT */ - if (!cpu0_initialized && (cpu_index == -1) && - (num_online_cpus() == 1)) { - cpu_index = 0; + apic_id = acpi_get_apicid(pr->handle, device_declaration, pr->acpi_id); + if (apic_id < 0) { + acpi_handle_err(pr->handle, "failed to get CPU APIC ID.\n"); + return -ENODEV; } + pr->apic_id = apic_id; - cpu0_initialized = 1; - + cpu_index = acpi_map_cpuid(pr->apic_id, pr->acpi_id); + if (!cpu0_initialized) { + cpu0_initialized = 1; + /* Handle UP system running SMP kernel, with no LAPIC in MADT */ + if ((cpu_index == -1) && (num_online_cpus() == 1)) + cpu_index = 0; + } pr->id = cpu_index; /* @@ -282,6 +285,7 @@ static int acpi_processor_get_info(struct acpi_device *device) if (ret) return ret; } + /* * On some boxes several processors use the same processor bus id. * But they are located in different scope. For example: -- 1.7.10.4 -- 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