Re: Incorrect uses of get_driver()/put_driver()

From: Dmitry Torokhov
Date: Mon Jan 09 2012 - 13:15:26 EST


On Mon, Jan 09, 2012 at 07:03:21PM +0100, Michael Büsch wrote:
> On Mon, 9 Jan 2012 12:35:09 -0500 (EST)
> Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
>
> > drivers/ssb/main.c:146: get_driver(&drv->drv);
> > drivers/ssb/main.c:153: put_driver(&drv->drv);
> >
> > Michael, these are part of ssb_driver_get() and ssb_driver_put(), used
> > in ssb_devices_freeze() and ssb_devices_thaw(). They don't currently
> > do anything, but it looks as if they are meant to prevent the driver
> > from being unloaded. Should they be replaced with try_module_get()?
> > Or would it be good enough to call device_attach() in
> > ssb_devices_thaw()?
>
> Hm, It seems that this code is trying to pin the ssb_driver, so that
> it doesn't become invalid during the freeze period. So it most likely wants
> to protect against module unload and driver unbind here. Not sure
> if that actually works, though :/
>

Not at all ;)

--
Dmitry
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