From 90b4f30b6d15222a509dacf47f29efef2b22571e Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 May 2017 16:30:12 +0200 Subject: [PATCH] hwmon: (coretemp) Handle frozen hotplug state correctly The recent conversion to the hotplug state machine missed that the original hotplug notifiers did not execute in the frozen state, which is used on suspend on resume. This does not matter on single socket machines, but on multi socket systems this breaks when the device for a non-boot socket is removed when the last CPU of that socket is brought offline. The device removal locks up the machine hard w/o any debug output. Prevent executing the hotplug callbacks when cpuhp_tasks_frozen is true. Thanks to Tommi for providing debug information patiently while I failed to spot the obvious. Fixes: e00ca5df37ad ("hwmon: (coretemp) Convert to hotplug state machine") Reported-by: Tommi Rantala Tested-by: Tommi Rantala Signed-off-by: Thomas Gleixner Signed-off-by: Guenter Roeck --- drivers/hwmon/coretemp.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c index 3ac4c03ba77b..c13a4fd86b3c 100644 --- a/drivers/hwmon/coretemp.c +++ b/drivers/hwmon/coretemp.c @@ -605,6 +605,13 @@ static int coretemp_cpu_online(unsigned int cpu) struct platform_data *pdata; /* + * Don't execute this on resume as the offline callback did + * not get executed on suspend. + */ + if (cpuhp_tasks_frozen) + return 0; + + /* * CPUID.06H.EAX[0] indicates whether the CPU has thermal * sensors. We check this bit only, all the early CPUs * without thermal sensors will be filtered out. @@ -654,6 +661,13 @@ static int coretemp_cpu_offline(unsigned int cpu) struct temp_data *tdata; int indx, target; + /* + * Don't execute this on suspend as the device remove locks + * up the machine. + */ + if (cpuhp_tasks_frozen) + return 0; + /* If the physical CPU device does not exist, just return */ if (!pdev) return 0; -- 2.11.0