Re: [PATCH v2] iio: light: tsl2583: Fix module unloading

[Jonathan Cameron]

On Fri, 9 Sep 2022 00:25:49 +0530
Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx> wrote:

> On 28/08/22 22:03, Jonathan Cameron wrote:
> > On Fri, 26 Aug 2022 17:53:52 +0530
> > Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx> wrote:
> >  
> >> tsl2583 uses devm_iio_device_register() function and
> >> calling iio_device_unregister() in remove breaks the
> >> module unloading.
> >> Fix this by using iio_device_register() instead of
> >> devm_iio_device_register() function in probe.  
> > Not sure why you are wrapping at 55 chars. I rewrapped this whilst applying.
> >
> > Reworded it a little too as I was touching it anyway.
> >
> > Applied to the fixes-togreg branch of iio.git.  
> 
> Hi Jonathan,
> 
> I was wondering if this got picked by you. I don't see it in 
> fixes-togreg that's why wanted to just confirm if you aren't looking for 
> some extra changes in this.
> 
> 
oops. I forgot to push that branch out. Done so now.

Jonathan

> Thanks
> Shreeya Patel
> 
> >  
> >> Cc: stable@xxxxxxxxxxxxxxx
> >> Fixes: 371894f5d1a0 ("iio: tsl2583: add runtime power management support")  
> > I took a look at this patch and it introduces the issue I just pointed
> > out in replying to your v1 by dropping the
> > /* Make sure the chip is on */
> > Which was correct even with runtime pm because it covered the case of
> > runtime_pm being disabled.   We probably need to bring that back as well,
> > perhaps as part of a cleanup patch taking this fully devm_
> >
> > This driver has another issue for working if runtime PM isn't built into
> > the kernel which is that it checks the return of pm_runtime_put_autosuspend()
> > which calls
> >
> > static inline int __pm_runtime_suspend(struct device *dev, int rpmflags)
> > {
> > 	return -ENOSYS;
> > }
> >
> > I've been meaning to do an audit for drivers that have this problem for
> > a while, but not yet gotten to it.
> >
> > An ideal IIO driver needs to work correctly whether or not CONFIG_PM is
> > enabled.
> >
> > Jonathan
> >
> >  
> >> Signed-off-by: Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx>
> >> ---
> >> Changes in v2
> >>    - Use iio_device_register() instead of devm_iio_device_register()
> >>    - Add fixes and stable tags
> >>
> >>   drivers/iio/light/tsl2583.c | 2 +-
> >>   1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/iio/light/tsl2583.c b/drivers/iio/light/tsl2583.c
> >> index 82662dab87c0..94d75ec687c3 100644
> >> --- a/drivers/iio/light/tsl2583.c
> >> +++ b/drivers/iio/light/tsl2583.c
> >> @@ -858,7 +858,7 @@ static int tsl2583_probe(struct i2c_client *clientp,
> >>   					 TSL2583_POWER_OFF_DELAY_MS);
> >>   	pm_runtime_use_autosuspend(&clientp->dev);
> >>   
> >> -	ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
> >> +	ret = iio_device_register(indio_dev);
> >>   	if (ret) {
> >>   		dev_err(&clientp->dev, "%s: iio registration failed\n",
> >>   			__func__);  
> >