From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Monjalon Subject: Re: [PATCH] e1000: fix the issue of wrongly reporting descriptor done Date: Sun, 02 Aug 2015 23:55:10 +0200 Message-ID: <1715977.YirRIvxXYr@xps13> References: <1438223940-12582-1-git-send-email-wenzhuo.lu@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: dev@dpdk.org To: Wenzhuo Lu Return-path: Received: from mail-wi0-f174.google.com (mail-wi0-f174.google.com [209.85.212.174]) by dpdk.org (Postfix) with ESMTP id 3B5DFC3D6 for ; Sun, 2 Aug 2015 23:56:26 +0200 (CEST) Received: by wibxm9 with SMTP id xm9so91318709wib.1 for ; Sun, 02 Aug 2015 14:56:26 -0700 (PDT) In-Reply-To: <1438223940-12582-1-git-send-email-wenzhuo.lu@intel.com> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 2015-07-30 10:39, Wenzhuo Lu: > Header buffer address for header split will be filled with the physical > address for DMA, which is actually not needed at all, as header split > hasn't been supported. Hardware requires the least bit of header address > which is 'Descriptor Done' bit when write back should be set to 0 by driver. > The issue is that if the user wants to reserve an odd number of bytes between > the mbuf header and data buffer, the physical address to be filled in the > descriptor would happen to be odd. That means the DD bit would be set to > non-zero by driver. That will result in reporting descriptor done wrongly. > > Signed-off-by: Wenzhuo Lu Applied, thanks