Re: [PATCH v4 2/2] iio: trigger: fix device initialization order in viio_trigger_alloc

[Nuno Sá]

On Mon, 2025-11-10 at 11:58 +0800, Ma Ke wrote:
> Move device initialization to the end of viio_trigger_alloc() to
> simplify error handling. This follows the pattern used in similar
> functions like spi_alloc_device(), where device_initialize() is called
> only after all resources have been successfully allocated.
> 
> This change eliminates the need for complex cleanup in error paths and
> ensures that the device release callback only runs when the device was
> fully initialized.
> 
> By moving device_initialize() after all resource allocations, we can
> use simple kfree() in error paths instead of put_device(), making the
> code more straightforward and less error-prone.
> 
> Found by code review.
> 
> Suggested-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
> Signed-off-by: Ma Ke <make24@xxxxxxxxxxx>
> ---

Have the same question Andy has... With that addressed:

Reviewed-by: Nuno Sá <nuno.sa@xxxxxxxxxx>

> Changes in v4:
> - split the patch into two independent patches and modified according to developer's suggestions;
> Changes in v3:
> - modified the patch;
> Changes in v2:
> - modified the patch, thanks for developer's suggestions.
> ---
>  drivers/iio/industrialio-trigger.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c
> index 5baa83349e8f..760ae3e60639 100644
> --- a/drivers/iio/industrialio-trigger.c
> +++ b/drivers/iio/industrialio-trigger.c
> @@ -562,12 +562,6 @@ struct iio_trigger *viio_trigger_alloc(struct device *parent,
>  	if (!trig)
>  		return NULL;
>  
> -	trig->dev.parent = parent;
> -	trig->dev.type = &iio_trig_type;
> -	trig->dev.bus = &iio_bus_type;
> -	device_initialize(&trig->dev);
> -	INIT_WORK(&trig->reenable_work, iio_reenable_work_fn);
> -
>  	mutex_init(&trig->pool_lock);
>  	trig->subirq_base = irq_alloc_descs(-1, 0,
>  					    CONFIG_IIO_CONSUMERS_PER_TRIGGER,
> @@ -593,6 +587,13 @@ struct iio_trigger *viio_trigger_alloc(struct device *parent,
>  				  IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
>  	}
>  
> +	/* Initialize device only after all resources are allocated */
> +	trig->dev.parent = parent;
> +	trig->dev.type = &iio_trig_type;
> +	trig->dev.bus = &iio_bus_type;
> +	device_initialize(&trig->dev);
> +	INIT_WORK(&trig->reenable_work, iio_reenable_work_fn);
> +
>  	return trig;
>  
>  free_descs: