On Monday, 13 August 2018 19:53:33 MSK Viresh Kumar wrote: > On 13 August 2018 at 22:13, Dmitry Osipenko <digetx@xxxxxxxxx> wrote: > > 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? > > Maybe you send a patch for this and take the credit as well :) Okay, I'll make the patch. Thank you for the help.
