Date: Wed, 21 Jan 2009 17:50:38 +0200 From: Andriy Gapon <avg@icyb.net.ua> To: Kostik Belousov <kostikbel@gmail.com> Cc: freebsd-hackers@freebsd.org Subject: Re: MOD_UNLOAD and driver with cdev Message-ID: <4977444E.8050306@icyb.net.ua> In-Reply-To: <20090121153908.GO58517@deviant.kiev.zoral.com.ua> References: <49773938.5010000@icyb.net.ua> <20090121153908.GO58517@deviant.kiev.zoral.com.ua>
next in thread | previous in thread | raw e-mail | index | archive | help
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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4977444E.8050306>