From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [net-2.6 PATCH] ixgbe: DCB, fix TX hang occurring in stress condition with PFC Date: Thu, 28 Oct 2010 10:20:34 -0700 (PDT) Message-ID: <20101028.102034.183041365.davem@davemloft.net> References: <20101028105957.27748.39154.stgit@localhost6.localdomain6> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, gospo@redhat.com, bphilips@novell.com, john.r.fastabend@intel.com To: jeffrey.t.kirsher@intel.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:45563 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933965Ab0J1RUK (ORCPT ); Thu, 28 Oct 2010 13:20:10 -0400 In-Reply-To: <20101028105957.27748.39154.stgit@localhost6.localdomain6> Sender: netdev-owner@vger.kernel.org List-ID: From: Jeff Kirsher Date: Thu, 28 Oct 2010 03:59:57 -0700 > From: John Fastabend > > The DCB credits refill quantum _must_ be greater than half the max > packet size. This is needed to guarantee that TX DMA operations > are not attempted during a pause state. Additionally, the min IFG > must be set correctly for DCB mode. If a DMA operation is > requested unexpectedly during the pause state the HW data > store may be corrupted leading to a DMA hang. The DMA hang > requires a reset to correct. This fixes the HW configuration > to avoid this condition. > > Signed-off-by: John Fastabend > Tested-by: Ross Brattain > Signed-off-by: Jeff Kirsher Applied.