[PATCH 3/6] i2c/pxa2xx: Add PCI support for PXA I2C controller

Sebastian Andrzej Siewior bigeasy at linutronix.de
Thu Jan 6 06:50:26 EST 2011

* Russell King - ARM Linux | 2011-01-06 11:12:31 [+0000]:

>Please see my email where I described the lifetime rules.  Let's say
>your module is removed.  In doing so, you call platform_device_unregister()
>followed by kfree().  After this, your module is removed from the system
>and the memory backing the module code is unmapped.
>If something holds a reference to the platform device, then that's just
>waiting for an OOPS to happen.  When those references are finally given
>up, your release function will be called - but the code has been unmapped.

I got that. That is why I'm going go to use allready provided functions
(platform_device_register_resndata() in this case) so I'm no longer
allocating any memory. So I'm only holding a struct which is pointing to
the platform_device. Everything else is unmapped by the driver core.

So I just have just to of_device_node_put() myself. Hmmm.

Grant, who is calling of_device_node_put() on nodes assigned in 
of_register_spi_devices() & of_i2c_register_devices()? I can't find any
reference. The spi part is not putting the node or removing the irq
mapping in error case so I guess there must be some magic triggered
Also adap->dev.of_node and master->dev.of_node has to be
non-null for the device assignment to work. Who is putting these nodes
back? I see drivers (i2c-cpm & i2c-mpc) taking refs but I fail to find a
place where it is put back.


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