Re: [alsa-devel] [PATCH v3 1/2] extcon: arizona: Add support for select accessory detect mode when headphone detection

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

On Wed, Apr 22, 2015 at 08:23:20PM +0900, Inha Song wrote:
> This patch add support for select accessory detect mode to HPDETL or HPDETR.
> Arizona provides a headphone detection circuit on the HPDETL and HPDETR pins
> to measure the impedance of an external load connected to the headphone.
> 
> Depending on board design, headphone detect pins can change to HPDETR or HPDETL.
> 
> Signed-off-by: Inha Song <ideal.song@samsung.com>
> ---
>  
> +static int arizona_extcon_of_get_pdata(struct arizona *arizona)
> +{
> +	struct arizona_pdata *pdata = &arizona->pdata;
> +	unsigned int val;

I would rather this is "unsigned int val =
ARIZONA_ACCDET_MODE_HPL;".

> +
> +	of_property_read_u32(arizona->dev->of_node, "wlf,hpdet-channel", &val);

Because this won't fill val if the DT entry isn't present.

> +	switch (val) {

Which means we hit this with val uninitialised.

> +	case ARIZONA_ACCDET_MODE_HPL:
> +	case ARIZONA_ACCDET_MODE_HPR:

So we may select either channel at random.

> +		pdata->hpdet_channel = val;
> +		break;
> +	default:
> +		dev_err(arizona->dev,
> +			"Wrong wlf,hpdet-channel DT value %d\n", val);

Or most likely just print an error but the DT being missing
shouldn't really be an error it is an optional entry.

> +		pdata->hpdet_channel = ARIZONA_ACCDET_MODE_HPL;
> +	}
> +
> +	return 0;
> +}

Thanks,
Charles