From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH 2/4 v2] netdev: bfin_mac: fix malformed UDP packet transmission when polling with KGDB Date: Fri, 29 May 2009 15:49:48 -0700 (PDT) Message-ID: <20090529.154948.232160792.davem@davemloft.net> References: <1243404615-25879-3-git-send-email-vapier@gentoo.org> <1243604443-27204-1-git-send-email-vapier@gentoo.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, uclinux-dist-devel@blackfin.uclinux.org, sonic.zhang@analog.com, cooloney@kernel.org To: vapier@gentoo.org Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:33953 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751472AbZE2Wts (ORCPT ); Fri, 29 May 2009 18:49:48 -0400 In-Reply-To: <1243604443-27204-1-git-send-email-vapier@gentoo.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Mike Frysinger Date: Fri, 29 May 2009 09:40:43 -0400 > From: Sonic Zhang > > Writes to the DMA descriptors may sit in the internal Blackfin data buffers > and not actually be available when the DMA engine goes to fetch them. This > does not typically happen, but when dealing with short/fast packets such as > UDP and polling KGDB, this occurs much more frequently. Same goes for > heavy loads as seen by netperf tests or large scp transfers. So force the > buffers to drain with SSYNC otherwise we get random malformed packets. > > Signed-off-by: Sonic Zhang > Signed-off-by: Mike Frysinger > Signed-off-by: Bryan Wu Applied to net-next-2.6