On 13 August 2018 at 21:36, Dmitry Osipenko <digetx@xxxxxxxxx> wrote: > I'm working on adding support of OPP and cooling for NVIDIA Tegra20/30 CPUFreq driver and stumbled upon a bug that is introduced by this patch. It is triggered on the driver module unload. The problem is that device_unregister() will end up freeing the cdev as well, so the current sequence is surely wrong. > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > index 6ab982309e6a..de53c821a282 100644 > --- a/drivers/thermal/thermal_core.c > +++ b/drivers/thermal/thermal_core.c > @@ -1102,8 +1102,8 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev) > mutex_unlock(&thermal_list_lock); > > ida_simple_remove(&thermal_cdev_ida, cdev->id); > - device_unregister(&cdev->device); > thermal_cooling_device_destroy_sysfs(cdev); > + device_unregister(&cdev->device); But this looks wrong as well, as the device is still around while memory of its sysfs data is gone. Maybe something like this is what we need: device_del(); thermal_cooling_device_destroy_sysfs(); device_put(); -- viresh
