[PATCH v2 1/5] thermal: intel: Fix dangling resources on thermal_throttle_online() failure

[Ricardo Neri]

The function thermal_throttle_add_dev() may fail and abort a CPU hotplug
online operation. Since the failure occurs within the online callback,
thermal_throttle_online(), the CPU hotplug framework does not invoke the
corresponding offline callback. As a result, the hardware and software
resources set up during the failed operation are not torn down.

Since only thermal_throttle_add_dev() can fail, call it before setting up
the rest of the resources.

Fixes: f6656208f04e ("x86/mce/therm_throt: Optimize notifications of thermal throttle")
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx>
---
Changes in v2:
 * Introduced this patch.
---
 drivers/thermal/intel/therm_throt.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/intel/therm_throt.c b/drivers/thermal/intel/therm_throt.c
index 44fa4dd15dd1..45a8ef4a608b 100644
--- a/drivers/thermal/intel/therm_throt.c
+++ b/drivers/thermal/intel/therm_throt.c
@@ -529,8 +529,13 @@ static int thermal_throttle_online(unsigned int cpu)
 {
 	struct thermal_state *state = &per_cpu(thermal_state, cpu);
 	struct device *dev = get_cpu_device(cpu);
+	int err;
 	u32 l;
 
+	err = thermal_throttle_add_dev(dev, cpu);
+	if (err)
+		return err;
+
 	state->package_throttle.level = PACKAGE_LEVEL;
 	state->core_throttle.level = CORE_LEVEL;
 
@@ -548,7 +553,7 @@ static int thermal_throttle_online(unsigned int cpu)
 	l = apic_read(APIC_LVTTHMR);
 	apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
 
-	return thermal_throttle_add_dev(dev, cpu);
+	return err;
 }
 
 static int thermal_throttle_offline(unsigned int cpu)

-- 
2.43.0