Bug in i2c-core?

Laurent Pinchart
2015-03-03T22:03:40Z

Hi Dmitry,

On Friday 27 February 2015 08:59:44 Dmitry Torokhov wrote:
> 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?).

Ouch, my bad.

Wolfram, any opinion ? The original patch fixes a real bug, so we shouldn't
just revert it.

--
Regards,

Laurent Pinchart