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

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Message-ID: <20171229162250.7d68a0c8@archlinux>
Date:   Fri, 29 Dec 2017 16:22:50 +0000
From:   Jonathan Cameron <jic23@...nel.org>
To:     Eugen Hristev <eugen.hristev@...rochip.com>
Cc:     <nicolas.ferre@...rochip.com>, <ludovic.desroches@...rochip.com>,
        <alexandre.belloni@...e-electrons.com>,
        <linux-iio@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <linux-input@...r.kernel.org>, <dmitry.torokhov@...il.com>
Subject: Re: [PATCH 10/14] iio: adc: at91-sama5d2_adc: force trigger removal
 on module remove

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

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);