From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Hartkopp Subject: Re: CAN documentation Date: Fri, 25 Jul 2014 16:03:47 +0200 Message-ID: <53D263C3.2090602@hartkopp.net> References: <1406296057.9487.1.camel@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mo4-p00-ob.smtp.rzone.de ([81.169.146.219]:61298 "EHLO mo4-p00-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760404AbaGYODu (ORCPT ); Fri, 25 Jul 2014 10:03:50 -0400 In-Reply-To: <1406296057.9487.1.camel@gmail.com> Sender: linux-can-owner@vger.kernel.org List-ID: To: Nikita Edward Baruzdin Cc: "linux-can@vger.kernel.org" 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. >