[PATCH v5 6/6] drm/bridge: sii902x: Implement HDMI audio support

[Jyri Sarha]

On 12/04/2019 15:30, Andrzej Hajda wrote:
>>>> +static const unsigned int sii902x_mclk_div_table[] = {
>>>> +	128, 256, 384, 512, 768, 1024, 1152, 192 };
>>>> +
>>>> +static int sii902x_select_mclk_div(u8 *i2s_config_reg, unsigned int rate,
>>>> +				   unsigned int mclk)
>>>> +{
>>>> +	unsigned int div = mclk / rate;
>>>> +	int distance = 100000;
>>>> +	u8 i, nearest = 0;
>>>> +
>>>> +	for (i = 0; i < ARRAY_SIZE(sii902x_mclk_div_table); i++) {
>>>> +		unsigned int d = abs(div - sii902x_mclk_div_table[i]);
>>> Using unsigned types in this context seems to be asking for troubles.
>>>
>> Why? Isn't return value of abs() by definition unsigned? Using signed
>> integers when comparing absolute distances would seem awkward to me.
> 
> (div - sii902x_mclk_div_table[i]) is unsigned, if div is lower, there is overflow, and the value is big int, I suppose this is not what you want.
> 

Oh yes. I had my eyes fixed on wrong unsigned. The first operand of
subtraction should indeed be signed for the result to be signed, I
completely overlooked that.

Thanks,
Jyri



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