From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Hartkopp Subject: Re: RFC: (optional) software filtering in candump Date: Wed, 19 Jun 2013 18:59:33 +0200 Message-ID: <51C1E375.3050600@hartkopp.net> References: <190D92B052C049F4B059DCFE8F841940@laptop2> <51BB5B80.9060109@hartkopp.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-2 Content-Transfer-Encoding: 7bit Return-path: Received: from mo-p00-ob.rzone.de ([81.169.146.161]:61775 "EHLO mo-p00-ob.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756835Ab3FSQ7f (ORCPT ); Wed, 19 Jun 2013 12:59:35 -0400 In-Reply-To: Sender: linux-can-owner@vger.kernel.org List-ID: To: Janusz Uzycki Cc: linux-can@vger.kernel.org, Krzysztof Borgulski >> Additional a hardware timestamp can be retrieved from the hardware and passed >> to the userspace. (HW timestamps) > > Thanks Oliver for the explanation. It's clean now. > Shouldn't hardware timestamping option be implemented like PTP? > http://lxr.linux.no/linux+v3.9.6/net/core/timestamping.c#L104 (I don't need > it but I couldn't find HW timestamp code for SJA1000 or MCP2515) Yes, that's missing. AFAIK only the PCAN USB (Pro) supports to pass the hardware timestamps to the userspace. But when i took a quick look into the output, i wasn't able to retrieve the HW timestamps. I wrote a fix for the driver: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/net/can/usb/peak_usb/pcan_usb.c?id=c9faaa09e2a1335678f09c70a0d0eda095564bab But i didn't manage to verify the HW timestamp output. It's on my list of things i wanted to investigate when i'm bored ;-) Regards, Oliver