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authorAlex Chiang <achiang@canonical.com>2010-06-17 09:08:54 -0600
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-02 10:30:24 -0700
commit3fd02a351fc8aa8602fe2b39d6a098ea2538db2e (patch)
treedb5db2c18deb2ec524342f9817954b0ee2e94bb5
parent92f61d8a31e270f9391e7bcc0ac638bd4262a8e0 (diff)
ACPI: processor: fix processor_physically_present on UP
commit 856b185dd23da39e562983fbf28860f54e661b41 upstream. The commit 5d554a7bb06 (ACPI: processor: add internal processor_physically_present()) is broken on uniprocessor (UP) configurations, as acpi_get_cpuid() will always return -1. We use the value of num_possible_cpus() to tell us whether we got an invalid cpuid from acpi_get_cpuid() in the SMP case, or if instead, we are UP, in which case num_possible_cpus() is #defined as 1. We use num_possible_cpus() instead of num_online_cpus() to protect ourselves against the scenario of CPU hotplug, and we've taken down all the CPUs except one. Thanks to Jan Pogadl for initial report and analysis and Chen Gong for review. https://bugzilla.kernel.org/show_bug.cgi?id=16357 Reported-by: Jan Pogadl <pogadl.jan@googlemail.com>: Reviewed-by: Chen Gong <gong.chen@linux.intel.com> Signed-off-by: Alex Chiang <achiang@canonical.com> Signed-off-by: Len Brown <len.brown@intel.com> Cc: Thomas Renninger <trenn@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/acpi/processor_core.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index 51284351418f..e9699aaed109 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -223,7 +223,7 @@ static bool processor_physically_present(acpi_handle handle)
type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
cpuid = acpi_get_cpuid(handle, type, acpi_id);
- if (cpuid == -1)
+ if ((cpuid == -1) && (num_possible_cpus() > 1))
return false;
return true;