Re: [PATCH] iio: trigger: Print an error if there is no available irq

[Martin Kelly <mkelly@xevo.com>]

On 2/13/19 5:17 AM, Mathieu Othacehe wrote:
> If there are more trigger consumers than
> CONFIG_IIO_CONSUMERS_PER_TRIGGER, iio_trigger_attach_poll_func will
> silently fail. Add an error message to inform the user that
> CONFIG_IIO_CONSUMERS_PER_TRIGGER limit might be exceeded.
> 
> Signed-off-by: Mathieu Othacehe <m.othacehe@gmail.com>
> ---
>   drivers/iio/industrialio-trigger.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c
> index ce66699c7fcc..801986c21467 100644
> --- a/drivers/iio/industrialio-trigger.c
> +++ b/drivers/iio/industrialio-trigger.c
> @@ -254,8 +254,12 @@ static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
>   
>   	/* Get irq number */
>   	pf->irq = iio_trigger_get_irq(trig);
> -	if (pf->irq < 0)
> +	if (pf->irq < 0) {
> +		pr_err("Could not find an available irq for trigger %s, "
> +			"CONFIG_IIO_CONSUMERS_PER_TRIGGER limit "
> +			"might be exceeded\n", trig->name);
>   		goto out_put_module;
> +	}
>   
>   	/* Request irq */
>   	ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
> 

This seems useful! I think it would be good to print the value of 
CONFIG_IIO_CONSUMERS_PER_TRIGGER too. Also, it appears this is 
triggering a checkpatch warning:

WARNING: quoted string split across lines