Re: [RFC] can: Introducing CANFD for af_can & can-raw

[Wolfgang Grandegger <wg@grandegger.com>]

Hi Kurt,

On 03/22/2012 10:57 AM, Kurt Van Dijck wrote:
> On Wed, Mar 21, 2012 at 04:05:28PM +0100, Oliver Hartkopp wrote:
>> On 21.03.2012 15:56, Wolfgang Grandegger wrote:
>>
>>>>>
>>>>> I think it's much more tricky to find a proper solution here.
>>>> As I mentioned before, I just use CAN_RAW with this. Actually, I just
>>>> ran a real CAN program that I wrote years ago. It still operates!
>>>
>>> Would you program still run if the payload is bigger than 8 bytes?
>>> I agree with Oliver.
>>
> The other side would have noticed at design time that it cannot
> send >8 bytes :-)
> 
> Did I miss something here? Is there a reason why existing programs
> may or should not work on a CANFD bus? I wanted to incorporate
> CANFD functionality _without_ putting an alternative API next to the
> current one, so to be able to use existing binaries on a future
> CANFD bus _without_ recompile (and thus not using the extras
> possibilities for that program).

I believe that 99% of the existing apps, including candump, do work with
a (hard-coded) maximum length of 8 bytes instead of a variable length.

Wolfgang.