From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH 17/20][BNX2]: Enhance the heartbeat. Date: Wed, 02 May 2007 00:24:26 -0700 (PDT) Message-ID: <20070502.002426.38687430.davem@davemloft.net> References: <1178068656.4820.53.camel@dell> <46383B00.4080605@garzik.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: mchan@broadcom.com, netdev@vger.kernel.org To: jeff@garzik.org Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:33600 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754909AbXEBHYa (ORCPT ); Wed, 2 May 2007 03:24:30 -0400 In-Reply-To: <46383B00.4080605@garzik.org> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Jeff Garzik Date: Wed, 02 May 2007 03:17:20 -0400 > Michael Chan wrote: > > [BNX2]: Enhance the heartbeat. > > > > In addition to the periodic heartbeat, we're adding a heartbeat > > request interrupt when the heartbeat is late. This is useful > > especially in -rt kernels where the timer frequently runs late. > > > > Signed-off-by: Michael Chan > > Should we really be adding code for such a special situation to upstream > code? > > I lean towards "no", but defer to your and DaveM's judgement here. My understanding of this situation is that if the timer is delayed a lot, which can happen with the -rt kernel, we don't send the heartbeat ping to the chip within the required margin. If the margin is not met, the ASF firmware takes this as a signal that the host system is down, and does things like reset the network card and other things we don't want it to do. Clarification from Michael would be appreciated, for sure.