Re: [PATCH v2 3/3] ASoC: TDA7802: Add turn-on diagnostic routine

[Charles Keepax <ckeepax@opensource.cirrus.com>]

On Tue, Jul 30, 2019 at 01:09:37PM +0100, Thomas Preston wrote:
> Add a debugfs device node which initiates the turn-on diagnostic routine
> feature of the TDA7802 amplifier. The four status registers (one per
> channel) are returned.
> 
> Signed-off-by: Thomas Preston <thomas.preston@codethink.co.uk>
> ---
> Changes since v1:
> - Rename speaker-test to (turn-on) diagnostics
> - Move turn-on diagnostic to debugfs as there is no standard ALSA
>   interface for this kind of routine.
> 
>  sound/soc/codecs/tda7802.c | 186 ++++++++++++++++++++++++++++++++++++-
>  1 file changed, 185 insertions(+), 1 deletion(-)
> 
> +static int tda7802_bulk_update(struct regmap *map, struct reg_update *update,
> +		size_t update_count)
> +{
> +	int i, err;
> +
> +	for (i = 0; i < update_count; i++) {
> +		err = regmap_update_bits(map, update[i].reg, update[i].mask,
> +				update[i].val);
> +		if (err < 0)
> +			return err;
> +	}
> +
> +	return i;
> +}

This could probably be removed using regmap_multi_reg_write.

> +static int tda7802_probe(struct snd_soc_component *component)
> +{
> +	struct tda7802_priv *tda7802 = snd_soc_component_get_drvdata(component);
> +	struct device *dev = &tda7802->i2c->dev;
> +	int err;
> +
> +	tda7802->debugfs = debugfs_create_dir(dev_name(dev), NULL);
> +	if (IS_ERR_OR_NULL(tda7802->debugfs)) {
> +		dev_info(dev,
> +			"Failed to create debugfs node, err %ld\n",
> +			PTR_ERR(tda7802->debugfs));
> +		return 0;
> +	}
> +
> +	mutex_init(&tda7802->diagnostic_mutex);
> +	err = debugfs_create_file("diagnostic", 0444, tda7802->debugfs, tda7802,
> +			&tda7802_diagnostic_fops);
> +	if (err < 0) {
> +		dev_err(dev,
> +			"debugfs: Failed to create diagnostic node, err %d\n",
> +			err);
> +		goto cleanup_diagnostic;
> +	}

You shouldn't be failing the driver probe if debugfs fails, it
should be purely optional.

Thanks,
Charles