linux-kernel - Warning seen when removing a module using irqdomain framework

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Date:   Tue, 23 Jul 2019 14:52:34 -0700
From:   pheragu@...eaurora.org
To:     marc.zyngier@....com, Linux Kernel <linux-kernel@...r.kernel.org>,
        Linux-arm Msm <linux-arm-msm@...r.kernel.org>
Cc:     psodagud@...eaurora.org, Tsoni <tsoni@...eaurora.org>,
        rananta@...eaurora.org, mnalajal@...eaurora.org
Subject: Warning seen when removing a module using irqdomain framework

Hi,

I have been working on a interrupt controller driver that uses tree 
based mapping for its domain (irq_domain_add_tree(..)).
If I understand correctly, the clients get a mapping when they call 
platform_get_irq(..).
However, after these clients are removed (rmmod), when I try to remove 
the interrupt controller driver where it calls irq_domain_remove(..), I 
hit this warning from kernel/kernel/irq/irqdomain.c:: 
irq_domain_remove(..)
[WARN_ON(!radix_tree_empty(&domain->revmap_tree));]-
WARNING: CPU: 0 PID: 238 at /kernel/kernel/irq/irqdomain.c:246 
irq_domain_remove+0x84/0x98

Also, I see that the requested IRQs by the clients are still present (in 
/proc/interrupts) even after they had been removed.
Hence, I just wanted to know how to handle this warning. Should the 
client clean up by calling irq_dispose_mapping(..) or is it the 
responsibility of the interrupt controller driver to dispose the 
mappings one by one?

Regards,
Prakruthi Deepak Heragu