Re: [PATCH 1/2] iio: Fix sign extension table in mcp3422 driver

[Jonathan Cameron <jic23@kernel.org>]

On 11/02/13 22:09, Angelo Compagnucci wrote:
> Hi Peter,
> 
> You are totally right, index is 0 based and this is a bug!
> 
> Thank your for fixing!
If you are happy with a patch that effects your code, the convention is
to reply with

Acked-by: Angelo Compagnucci <angelo.compagnucci@gmail.com>

to indicate this in the commit log.

Do you mind me adding that to this patch?
> 
> 2013/11/2 Peter Meerwald <pmeerw@pmeerw.net>:
>> the index argument to sign_extend32() gives the bit position (from 0)
>> to the sign bit
>>
>> so e.g. if the measurement has 16-bit resolution, we need to pass 15;
>> a measurement of 0x8000 should be reported as -32768, not 32768
>>
>> Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
>> Cc: Angelo Compagnucci <angelo.compagnucci@gmail.com>
>> ---
>>  drivers/iio/adc/mcp3422.c | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/iio/adc/mcp3422.c b/drivers/iio/adc/mcp3422.c
>> index 1294832..c8c1baa 100644
>> --- a/drivers/iio/adc/mcp3422.c
>> +++ b/drivers/iio/adc/mcp3422.c
>> @@ -88,10 +88,10 @@ static const int mcp3422_sample_rates[4] = {
>>
>>  /* sample rates to sign extension table */
>>  static const int mcp3422_sign_extend[4] = {
>> -       [MCP3422_SRATE_240] = 12,
>> -       [MCP3422_SRATE_60] = 14,
>> -       [MCP3422_SRATE_15] = 16,
>> -       [MCP3422_SRATE_3] = 18 };
>> +       [MCP3422_SRATE_240] = 11,
>> +       [MCP3422_SRATE_60] = 13,
>> +       [MCP3422_SRATE_15] = 15,
>> +       [MCP3422_SRATE_3] = 17 };
>>
>>  /* Client data (each client gets its own) */
>>  struct mcp3422 {
>> --
>> 1.8.4.2
>>
> 
> 
>