From patchwork Fri Jul 12 18:01:16 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: George Spelvin X-Patchwork-Id: 258779 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 38EDC2C0362 for ; Sat, 13 Jul 2013 04:01:22 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965194Ab3GLSBS (ORCPT ); Fri, 12 Jul 2013 14:01:18 -0400 Received: from science.horizon.com ([71.41.210.146]:25056 "HELO science.horizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S965004Ab3GLSBR (ORCPT ); Fri, 12 Jul 2013 14:01:17 -0400 Received: (qmail 21177 invoked by uid 1000); 12 Jul 2013 14:01:16 -0400 Date: 12 Jul 2013 14:01:16 -0400 Message-ID: <20130712180116.21176.qmail@science.horizon.com> From: "George Spelvin" To: grantgrundler@gmail.com, linux@horizon.com Subject: Re: [RFC] tulip: Support for byte queue limits Cc: eric.dumazet@gmail.com, grundler@parisc-linux.org, netdev@vger.kernel.org In-Reply-To: Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > Hi George, > While you are right that functionally it doesn't matter, my preference > would be to have nothing between the wmb() and iowrite() that kicks > off the TX. This marginally helps kick off the TX process consistently > slightly sooner. On modern HW, probably irrelevant, but not on the HW > these chips are used on. I'll revise it. It just made sense to me to put it next to the other bookkeeping line of tp->cur_tx++. Should I move them both below the iowrite()? As in: > Lastly, given I haven't powered up a system in two years which has > tulip, any one want to take over maintainer for tulip driver? > It's basically obsolete with a few rare patches like this one coming in. I'm not up to it myself, sorry. --- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- a/drivers/net/ethernet/dec/tulip/tulip_core.c +++ b/drivers/net/ethernet/dec/tulip/tulip_core.c @@ -702,11 +702,11 @@ tulip_start_xmit(struct sk_buff *skb, struct net_device *dev) tp->tx_ring[entry].status = cpu_to_le32(DescOwned); wmb(); - tp->cur_tx++; - /* Trigger an immediate transmit demand. */ iowrite32(0, tp->base_addr + CSR1); + tp->cur_tx++; + netdev_sent_queue(dev, skb->len); spin_unlock_irqrestore(&tp->lock, flags); return NETDEV_TX_OK;