From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH 2/4] e1000: add module option to set transmit descriptor size Date: Fri, 27 Jun 2008 01:10:37 -0400 Message-ID: <4864764D.6070802@garzik.org> References: <20080619211850.GD22981@gospo.rdu.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, jeffrey.t.kirsher@intel.com, jesse.brandeburg@intel.com To: Andy Gospodarek Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:40692 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752068AbYF0FKl (ORCPT ); Fri, 27 Jun 2008 01:10:41 -0400 In-Reply-To: <20080619211850.GD22981@gospo.rdu.redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: Andy Gospodarek wrote: > This patch added the TxDescPower parameter to the e1000 module. This > parameter represents the size-order of each transmit descriptor. The > valid size for descriptors would be 2^7 (128) - 2^12 (4096) bytes each. > As this value decreases one may want to consider increasing the > TxDescriptors value to maintain the same amount of frame memory. This > patch does not change the defaults for any particular hardware model, so > this will not have an effect on existing users. > > The purpose of the patch is to address Tx Timeouts on 82545 and 82546 > chips that can show up during high-stress situations. Decreasing the > transmit descriptor size can shorten the amount of time that will be > spent DMAing frames to the hardware and can reduce the likely-hood that > Tx Timeouts will occur. > > Signed-off-by: Andy Gospodarek > --- > drivers/net/e1000/e1000.h | 6 ++++++ > drivers/net/e1000/e1000_main.c | 12 ++---------- > drivers/net/e1000/e1000_param.c | 33 +++++++++++++++++++++++++++++++++++ > 3 files changed, 41 insertions(+), 10 deletions(-) I don't see why a module parameter is needed. In practice, nobody will ever think about this option, much less use it.