Hi Luiz,
On 30 March 2015 at 11:39, Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx> wrote:
> Hi Grzegorz,
>
> On Mon, Mar 30, 2015 at 11:45 AM, Grzegorz Kolodziejczyk
> <grzegorz.kolodziejczyk@xxxxxxxxx> wrote:
>> Conversion from be to le can be done using bluetooth funcion.
>> ---
>> lib/uuid.c | 6 ++----
>> 1 file changed, 2 insertions(+), 4 deletions(-)
>>
>> diff --git a/lib/uuid.c b/lib/uuid.c
>> index 15fbd66..2f598b8 100644
>> --- a/lib/uuid.c
>> +++ b/lib/uuid.c
>> @@ -338,15 +338,13 @@ int bt_uuid_strcmp(const void *a, const void *b)
>>
>> int bt_uuid_to_le(const bt_uuid_t *src, void *dst)
>> {
>> - bt_uuid_t uuid;
>> -
>> switch (src->type) {
>> case BT_UUID16:
>> bt_put_le16(src->value.u16, dst);
>> return 0;
>> case BT_UUID32:
>> - bt_uuid_to_uuid128(src, &uuid);
>> - /* Fallthrough */
>> + bt_put_le32(src->value.u32, dst);
>> + return 0;
>
> I think the idea is to either use 16 or 128 bits format and never 32
> bits thus the reason why we convert to 32 to 128, btw 128 format is in
> fact a byte arrays therefore endianess conversion per architecture
> don't apply, we do have a convention to define the array in big endian
> format, thus we always need to swap.
>
I agree that conversion to 128-bit value is needed if somehow we would
like to process this 32-bit uuid, but this is a little bit confusing
that change of byte ordering make internal conversion. It looks like
lib/uuid is prepared to process 32 bit values, we have functions like
create 32bit uuid, convert to 32bit uuid, string to uuid 32.
Btw. original code anyway looks bad. Conversion 32bit-128bit is from
src uuid_t to uuid and then swap is on non existing/not set u128 src
value (src has set u32), uuid variable is omitted.
>> case BT_UUID128:
>> /* Convert from 128-bit BE to LE */
>> bswap_128(&src->value.u128, dst);
>> --
>> 2.1.0
>
>
>
>
> --
> Luiz Augusto von Dentz
BR,
Grzegorz
--
To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
