Subject: Bug in i2c-core?

From: [email-masked] (Dmitry Torokhov)
Date: Fri, 27 Feb 2015 08:59:44 -0800

On Fri, Feb 27, 2015 at 12:09:51PM +0100, S?bastien SZYMANSKI wrote:
> Hi,
> 
> I am writing an I2C touchscreen driver for an i.MX6 based board. I
> compiled it as a module and when I unload it, I get the following warning:
> 
> # modprobe sx8654
> [   46.261494] input: SX8654 I2C Touchscreen as
> /devices/soc0/soc/2100000.aips-bus/21a0000.i2c/i2c-0/0-0048/input/input1
> # rmmod sx8654
> [   76.435223] ------------[ cut here ]------------
> [   76.439909] WARNING: CPU: 0 PID: 134 at fs/proc/generic.c:552
> remove_proc_entry+0x148/0x164()
> [   76.448582] remove_proc_entry: removing non-empty directory
> 'irq/208', leaking at least 'sx8654'

...

> When I revert commit e4df3a0 (i2c: core: Dispose OF IRQ mapping at
> client removal time) I don't get the warning.
> 
> Is this a bug in the i2c-core or am I doing something wrong in my driver?

Yes, this commit breaks all drivers using devm* for IRQ management on
OF-based systemsi because devm* cleanup happens in device code, after
bus's remove() method returns. I'd recommend reverting and finding a
better way (making cleanup a custom devm action as well?).

Thanks.

-- 
Dmitry