diff options
authorThomas Renninger <trenn@suse.de>2012-07-12 12:24:33 +0200
committerRafael J. Wysocki <rjw@sisk.pl>2012-07-12 22:39:32 +0200
commitc4686c71a9183f76e3ef59098da5c098748672f6 (patch)
parentbd0a521e88aa7a06ae7aabaed7ae196ed4ad867a (diff)
cpufreq / ACPI: Fix not loading acpi-cpufreq driver regression
Commit d640113fe80e45ebd4a5b420b introduced a regression on SMP systems where the processor core with ACPI id zero is disabled (typically should be the case because of hyperthreading). The regression got spread through stable kernels. On 3.0.X it got introduced via 3.0.18. Such platforms may be rare, but do exist. Look out for a disabled processor with acpi_id 0 in dmesg: ACPI: LAPIC (acpi_id[0x00] lapic_id[0x10] disabled) This problem has been observed on a: HP Proliant BL280c G6 blade This patch restricts the introduced workaround to platforms with nr_cpu_ids <= 1. Signed-off-by: Thomas Renninger <trenn@suse.de> CC: stable@vger.kernel.org Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index c850de4c9a14..eff722278ff5 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -189,10 +189,12 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
* Processor (CPU3, 0x03, 0x00000410, 0x06) {}
* }
- * Ignores apic_id and always return 0 for CPU0's handle.
+ * Ignores apic_id and always returns 0 for the processor
+ * handle with acpi id 0 if nr_cpu_ids is 1.
+ * This should be the case if SMP tables are not found.
* Return -1 for other CPU's handle.
- if (acpi_id == 0)
+ if (nr_cpu_ids <= 1 && acpi_id == 0)
return acpi_id;
return apic_id;