On Monday, 13 August 2018 19:21:43 MSK Viresh Kumar wrote: > 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. Indeed. > Maybe something like this is what we need: > > device_del(); > thermal_cooling_device_destroy_sysfs(); > device_put(); [I just realized that thermal_zone and cooling_device are not interrelated. I'm not familiar with the thermal/ code] Thank you Viresh, your proposal looks good to me and works fine. Will you make a proper patch?
