Re: [PATCH v2] irq: generic-chip: provide irq_free_generic_chip()

From: Thomas Gleixner
Date: Thu Mar 09 2017 - 05:17:38 EST


On Wed, 8 Mar 2017, Bartosz Golaszewski wrote:

> Some users of irq_alloc_generic_chip() are modules which can be
> removed (e.g. gpio-ml-ioh) but have no means of freeing the allocated
> generic chip. Provide a function for that.

They have means, i.e. kfree(gc). If you want a wrapper for that then please
make it a simple static inline w/o the bloat of an exported symbol.

But, what you really want is a proper counterpart to
irq_alloc_generic_chip() which undoes everything what
irq_alloc_generic_chip() does.

You have to call irq_remove_generic_chip() before calling kfree() or the
wrapper anyway. And looking at the 3 users of irq_remove_generic_chip():

Two of them (drivers/gpio/gpio-tb10x.c drivers/mfd/jz4740-adc.c) do

irq_remove_generic_chip(gc)
kfree(gc)

The third one (arch/arm/mach-omap2/prm_common.c) leaks the generic chip
memory....

So the proper solution is to rename irq_remove_generic_chip() to
irq_destroy_generic_chip() and do the kfree() at the end of that function.

Hmm?

tglx