ath6kl: fix uninitialized variable in ath6kl_sdio_enable_scatter()
[pandora-kernel.git] / drivers / acpi / processor_core.c
index 3a0428e..eff7222 100644 (file)
@@ -173,8 +173,32 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
        apic_id = map_mat_entry(handle, type, acpi_id);
        if (apic_id == -1)
                apic_id = map_madt_entry(type, acpi_id);
-       if (apic_id == -1)
-               return apic_id;
+       if (apic_id == -1) {
+               /*
+                * On UP processor, there is no _MAT or MADT table.
+                * So above apic_id is always set to -1.
+                *
+                * BIOS may define multiple CPU handles even for UP processor.
+                * For example,
+                *
+                * Scope (_PR)
+                 * {
+                *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
+                *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
+                *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
+                *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
+                * }
+                *
+                * 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 (nr_cpu_ids <= 1 && acpi_id == 0)
+                       return acpi_id;
+               else
+                       return apic_id;
+       }
 
 #ifdef CONFIG_SMP
        for_each_possible_cpu(i) {