From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Egnor Subject: Re: Fwd: Querying current =?utf-8?b?dHhfcXVldWU=?= usage of a SocketCAN interface Date: Wed, 1 Apr 2015 20:57:40 +0000 (UTC) Message-ID: References:

<55187FF1.7020701@optusnet.com.au> <5519E5A9.7080104@optusnet.com.au> <551A0FF3.4070400@optusnet.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from plane.gmane.org ([80.91.229.3]:53627 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751158AbbDAVAI (ORCPT ); Wed, 1 Apr 2015 17:00:08 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1YdPk2-0006x8-QF for linux-can@vger.kernel.org; Wed, 01 Apr 2015 23:00:03 +0200 Received: from 216.239.45.65 ([216.239.45.65]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 01 Apr 2015 23:00:02 +0200 Received: from dan.egnor by 216.239.45.65 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 01 Apr 2015 23:00:02 +0200 Sender: linux-can-owner@vger.kernel.org List-ID: To: linux-can@vger.kernel.org Paarvai Naai gmail.com> writes: > I have a suspicion that SocketCAN implementations are not careful > about doing this, even though particular controllers may support this > type of re-prioritization of frames (with their own internal TX > queues). Actually I think this is a problem even if you have one process -- a higher priority message can get stuck behind a lower priority message (priority inversion). Is there any way to deal with this, assuming that one node wants to send both high priority and low priority messages? There must be a solution, otherwise half the point of CAN (prioritized messages) would be lost...! -- egnor