CAN documentation

CAN documentation

[Nikita Edward Baruzdin]

Hello, guys,

I'm looking at linux-can/can-modules tree:

2011-06-26 12:47 Oliver Hartkopp
  minor doc changes ... tbc

2011-06-10 19:08 Oliver Hartkopp
  documentation: rework chapter numbering & references

...

2010-11-22 19:41 Oliver Hartkopp
  Added new documentation layout contributed by Daniele Venzano.

Why are all these changes still not in the kernel? I'm not sure if this
is a good idea to split the documentation, but the patches introduce
some new helpful information.

Hence a little follow-up question:

> The timestamp on Linux has a resolution of one microsecond and it is
> set automatically at the reception of a CAN frame.

It seems to me this is not entirely true as the kernel has a support for
SO_TIMESTAMPNS socket option for quite a long time. Could you really use
that option with CAN? Does it make sense to use nanosecond timestamps?
I'm also a bit confused whether these are only the software timestamps
or you can somehow get them from a controller too.

Re: CAN documentation

[Oliver Hartkopp]

Hi Nikita,

indeed the BCM patches have been added to the tree as well as
CAN FD and filter documentation updates, see commit log at:

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/log/Documentation/networking/can.txt

Don't know if it's really useful to split up the file.

Would you like to provide a patch for the timestamping stuff?

Regards,
Oliver


On 25.07.2014 15:47, Nikita Edward Baruzdin wrote:
> Hello, guys,
> 
> I'm looking at linux-can/can-modules tree:
> 
> 2011-06-26 12:47 Oliver Hartkopp
>   minor doc changes ... tbc
> 
> 2011-06-10 19:08 Oliver Hartkopp
>   documentation: rework chapter numbering & references
> 
> ...
> 
> 2010-11-22 19:41 Oliver Hartkopp
>   Added new documentation layout contributed by Daniele Venzano.
> 
> Why are all these changes still not in the kernel? I'm not sure if this
> is a good idea to split the documentation, but the patches introduce
> some new helpful information.
> 
> Hence a little follow-up question:
> 
>> The timestamp on Linux has a resolution of one microsecond and it is
>> set automatically at the reception of a CAN frame.
> 
> It seems to me this is not entirely true as the kernel has a support for
> SO_TIMESTAMPNS socket option for quite a long time. Could you really use
> that option with CAN? Does it make sense to use nanosecond timestamps?
> I'm also a bit confused whether these are only the software timestamps
> or you can somehow get them from a controller too.
>