Re: [PATCH v4 4/5] can: bcm: add support for CAN FD frames

[Oliver Hartkopp <socketcan@hartkopp.net>]

On 06/17/2016 12:23 PM, Marc Kleine-Budde wrote:
> On 06/04/2016 09:26 PM, Oliver Hartkopp wrote:

>> -/* easy access to CAN frame payload */
>> -static inline u64 GET_U64(const struct can_frame *cp)
>> +/* easy access to the first 64 bit of can(fd)_frame payload */
>> +static inline u64 GET_U64(const struct canfd_frame *cp, int offset)
>>   {
>> -	return *(u64 *)cp->data;
>> +	return *(u64 *)(cp->data + offset);
>
> Can you ensure that offset is always a multiple of 8?

I would like to put that into a comment, as a check for this helper at 
runtime is too expensive - and the caller is only in this C-file at two 
places.

> Unaligned pointer
> access will be quite slow on some platforms.

cp->data is well aligned.

> Can you please make this
> function lower-case (as it's a function not a macro).

will do.

Tnx,
Oliver