Looks good to me. (perhaps a bit more detail in the commit
message of the patch?)
Acked-by: Jonathan Cameron <jic23@xxxxxxxxx>
> Jonathan Cameron wrote:
>> Michele De Candia (VT) wrote:
>>
>>> Hi all,
>>>
>>> I've tested TSL2550 driver and I've found a bug: when light is off,
>>> returned value from tsl2550_calculate_lux function is -1 when it should
>>> be 0 (sensor correctly read that light was off).
>>>
>>> I think the bug is that a zero c0 value (approximated value of ch0) is
>>> misinterpreted as an error.
>>> I'm attaching you a patch that fixes the bug.
>>>
>>> Regards,
>>> Michele Jr De Candia
>>>
>> Sounds reasonable, but I think a stray line got away in your patch
>> (see below)
>> Not to mention, if the c1 <= c0 check is still valid, should you not also
>> confirm that c1 == 0 as well? Perhaps reverse the ordering?
>>
> That's right. A new patch can be found in attachment.
>> if (c1 <= c0)
>> if(c0) {
>> r = c1* 128 / c0;
>> lux = ((c0 - c1) * ratio_lut[r]) / 256;
>> } else
>> lux = 0;
>> else
>> return -1;
>>
>>
>> Signed-off-by: Michele Jr De Candia <michele.decandia@xxxxxxxxxxxxx>
>>
>> diff --git a/drivers/i2c/chips/tsl2550.c b/drivers/i2c/chips/tsl2550.c
>> index 1a9cc13..6bad072 100644
>> --- a/drivers/i2c/chips/tsl2550.c
>> +++ b/drivers/i2c/chips/tsl2550.c
>> @@ -189,10 +189,16 @@ static int tsl2550_calculate_lux(u8 ch0, u8 ch1)
>> u8 r = 128;
>>
>> /* Avoid division by 0 and count 1 cannot be greater than count 0 */
>> - if (c0 && (c1 <= c0))
>> - r = c1 * 128 / c0;
>> - else
>> - return -1;
>> + if (c0) {
>> + if (c1 <= c0)
>> + r = c1 * 128 / c0;
>> + else
>> + return -1;
>> +
>> + /* Calculate LUX */
>> + lux = ((c0 - c1) * ratio_lut[r]) / 256;
>> + }
>> + else lux = 0;
>>
>>
>> This last line should have been removed I think?
>> /* Calculate LUX */
>> lux = ((c0 - c1) * ratio_lut[r]) / 256;
>>
>> ---
>> Jonathan Cameron
>>
>>
> Than
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