Messages in this thread |  | | Subject | Re: Clarifying platform_device_unregister | From | Richard Purdie <> | Date | Sat, 05 Apr 2008 12:44:52 +0100 |
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On Tue, 2008-04-01 at 10:54 -0400, Dmitry Torokhov wrote: > On Tue, Apr 01, 2008 at 12:47:54AM -0700, Jaya Kumar wrote: > > That's interesting. I noticed though that a lot of platform device > > code assigns a statically allocated structure to platform_data. For > > example: > > > > arch/arm/mach-pxa/corgi_pm.c > > static struct sharpsl_charger_machinfo corgi_pm_machinfo = { > > ... > > } > > corgipm_device->dev.platform_data = &corgi_pm_machinfo; > > > > same with spitz_pm.c. > > > > egrep "platform_data.*=.*\&" *.c shows quite a lot of users doing > > that. I guess most of these below are probably okay since these > > drivers can't be rmmoded. > > > > Hmm, are you sure they can't be removed? Why do they all have > module_exit methods? > > Even if they can't be unloaded the whole thing will blow to pieces > if registration fails. Consider this: > > static int __devinit spitzpm_init(void) > { > int ret; > > spitzpm_device = platform_device_alloc("sharpsl-pm", -1); > if (!spitzpm_device) > return -ENOMEM; > > spitzpm_device->dev.platform_data = &spitz_pm_machinfo; > ret = platform_device_add(spitzpm_device); > > if (ret) > platform_device_put(spitzpm_device); > ^^^^^^^^^^^ > This will try to kfree(spitzpm_device->dev.platform_data) and it gonna > blow. We need to do spitzpm_device->dev.platform_data = NULL before doing > put. > > Also spitzpm_init() shoudl be marked __init, not __devinit and > spitzpm_exit() should be __exit() if it is event needed at all. > > Richard, I think you work with spitz and corgi, any comments?
Looking at this I agree there are some problems there.
In the real world the spitz/corgi devices are pretty useless without power management and therefore these code paths aren't well used. I think this has happened since the platform data was a later addition to the code and the internal use of kfree on platform_data wasn't realised.
I'll make sure some patches are submitted to address these issues.
Cheers,
Richard
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