[PATCH v5 2/4] acpi_processor: do not mark present at boot but not onlined CPU as onlined

[Igor Mammedov]

acpi_processor_add() assumes that present at boot CPUs
are always onlined, it is not so if a CPU failed to become
onlined. As result acpi_processor_add() will mark such CPU
device as onlined in sysfs and following attempts to
online/offline it using /sys/device/system/cpu/cpuX/online
attribute will fail.

Do not poke into device internals in acpi_processor_add()
and touch "struct device { .offline }" attribute, since
for CPUs onlined at boot it's set by:
  topology_init() -> arch_register_cpu() -> register_cpu()
before ACPI device tree is parsed, and for hotplugged
CPUs it's set when userspace onlines CPU via sysfs.

Signed-off-by: Igor Mammedov <imammedo@xxxxxxxxxx>
Acked-by: Toshi Kani <toshi.kani@xxxxxx>
---
v2:
 - fix regression in v1 leading to NULL pointer dereference
   on CPU unplug, do not remove "pr->dev = dev;"
---
 drivers/acpi/acpi_processor.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index b06f5f5..52c81c4 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -405,7 +405,6 @@ static int acpi_processor_add(struct acpi_device *device,
 		goto err;
 
 	pr->dev = dev;
-	dev->offline = pr->flags.need_hotplug_init;
 
 	/* Trigger the processor driver's .probe() if present. */
 	if (device_attach(dev) >= 0)
-- 
1.7.1

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