Re: [PATCH 10/14] iio: adc: at91-sama5d2_adc: force trigger removal on module remove

From: Jonathan Cameron
Date: Fri Dec 29 2017 - 11:23:03 EST


On Fri, 22 Dec 2017 17:07:17 +0200
Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx> wrote:

> On module remove, if we do not call trigger remove, the trigger
> stays in the subsystem, and on further module insert, we will have
> multiple triggers, and the old one is not usable.
> Have to call the remove function on module remove to solve this.
>
> Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>

This needs more explanation. I can't see why the managed removal
isn't sufficient. On removal the dev should have gone away taking
the trigger with it.

If it isn't then it looks like a straight forward bug that needs fixing.

Jonathan

> ---
> drivers/iio/adc/at91-sama5d2_adc.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
> index 4eff835..7b9febc 100644
> --- a/drivers/iio/adc/at91-sama5d2_adc.c
> +++ b/drivers/iio/adc/at91-sama5d2_adc.c
> @@ -1180,6 +1180,9 @@ static int at91_adc_remove(struct platform_device *pdev)
> struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> struct at91_adc_state *st = iio_priv(indio_dev);
>
> + if (st->selected_trig->hw_trig)
> + devm_iio_trigger_unregister(&indio_dev->dev, st->trig);
> +
> iio_device_unregister(indio_dev);
>
> at91_adc_dma_disable(pdev);