Messages in this thread |  | | | Date | Tue, 3 Nov 2009 18:31:54 +0100 | | From | Antonio Ospite <> | | Subject | Re: Using statically allocated memory for platform_data. |
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On Mon, 2 Nov 2009 16:47:44 +0000 Ben Dooks <ben-linux@fluff.org> wrote: > On Mon, Nov 02, 2009 at 04:37:01PM +0000, Russell King - ARM Linux wrote: > > On Mon, Nov 02, 2009 at 04:28:39PM +0000, Ben Dooks wrote: > > > On Mon, Nov 02, 2009 at 03:56:25PM +0000, Russell King - ARM Linux wrote: > > > > The reason we have platform_device_add_data() is that people think that > > > > the device data needs to persist for the lifetime of the device. I > > > > personally disagree with that - once you unregister the device, it's > > > > guaranteed that device drivers will have been unregistered, so who's > > > > going to use the platform data? > > > > > > That doesn't make any sense, in the current case of using the > > > platform_device_alloc() and those calls the data is only living > > > for the lifetime of the device, as the release call is tidying up > > > the result. > > > > What I'm saying is that the lifetime of the data finishes once > > the _unregister() call has returned. So: > > > > data = pdev->dev.platform_data; > > platform_device_unregister(pdev); > > kfree(data); > > > > is an entirely valid way of handling the "I allocated my platform > > data" problem - it doesn't need to exist to the point where the > > device itself is freed. > > Unforutnately pretty much everyone now assumes that the act of > unregistering the device will get rid of the data that the allocated > by the add functions. > > This would mean going around fixing a number of current drivers which > all make that assumption. >
So those drivers (ezx-pcap.c, da903x.c) aren't doing anything manifestly wrong by not calling platform_device_add_data(), and the issue will be solved in ./drivers/base/platform.c someway eventually, right?
Thanks, Antonio
-- Antonio Ospite http://ao2.it
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