MOD_UNLOAD and driver with cdev

[Andriy Gapon]

on 21/01/2009 17:39 Kostik Belousov said the following:
> On Wed, Jan 21, 2009 at 05:03:20PM +0200, Andriy Gapon wrote:
>> Do I need to code for MOD_UNLOAD for driver module that also creates a cdev?
>> I see in the current code that one strategy is to simply call
>> destroy_dev(). I guess detach routines are called automatically and
>> destroy_dev can be done there as well..
> What are the detach routines ? Do you mean newbus device detach ?

Yes, device_detach. This seems to work and make_device_driver.sh also
suggests it this way. But I am not sure about possible races.

> Yes, the usual strategy is to call destroy_dev from unload handler.
> 
>> Is it reasonable to refuse unload if cdev is in use (in MOD_QUIESCE)?
>> How to check for that best?
> 
> This cannot be checked race-free.

So no point in trying?


-- 
Andriy Gapon