[alsa-devel] [PATCH - alsa-lib 1/3] tlv: Check out of range dB with SND_CTL_TLVT_DB_RANGE

[Takashi Iwai]

At Mon, 19 Jul 2010 10:14:04 +0300,
Peter Ujfalusi wrote:
> 
> When converting from dB value to raw value, the control's
> full range was not checked in case of SND_CTL_TLVT_DB_RANGE.
> 
> Check out of range dB values, and return apropriate raw
> value for the caller.
> 
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi at nokia.com>
> ---
>  src/control/tlv.c |    9 ++++++++-
>  1 files changed, 8 insertions(+), 1 deletions(-)
> 
> diff --git a/src/control/tlv.c b/src/control/tlv.c
> index 0ff052e..d09766a 100644
> --- a/src/control/tlv.c
> +++ b/src/control/tlv.c
> @@ -285,13 +285,20 @@ int snd_tlv_convert_from_dB(unsigned int *tlv, long rangemin, long rangemax,
>  {
>  	switch (tlv[0]) {
>  	case SND_CTL_TLVT_DB_RANGE: {
> +		long dbmin, dbmax;
>  		unsigned int pos, len;
>  		len = int_index(tlv[1]);
>  		if (len > MAX_TLV_RANGE_SIZE)
>  			return -EINVAL;
> +		if (snd_tlv_get_dB_range(tlv, rangemin, rangemax,
> +					 &dbmin, &dbmax))
> +			return -EINVAL;
> +		if (db_gain <= dbmin || db_gain >= dbmax) {
> +			*value = db_gain <= dbmin ? rangemin : rangemax;
> +			return 0;
> +		}

The check looks good, but IMO, just plain two if's are more intuitive:

		if (db_gain <= dbmin) {
			*value = rangemin;
			return 0;
		} else if (db_gain >= dbmax) {
			*value = rangemax;
			return 0;
		}

thanks,

Takashi