From patchwork Thu Mar 12 23:07:54 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jaeden Amero X-Patchwork-Id: 449692 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 270741400EA for ; Fri, 13 Mar 2015 10:08:27 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756094AbbCLXII (ORCPT ); Thu, 12 Mar 2015 19:08:08 -0400 Received: from skprod2.natinst.com ([130.164.80.23]:45807 "EHLO ni.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755356AbbCLXIH (ORCPT ); Thu, 12 Mar 2015 19:08:07 -0400 Received: from us-aus-mgwout1.amer.corp.natinst.com (nb-snip2-1338.natinst.com [130.164.19.135]) by us-aus-skprod2.natinst.com (8.15.0.59/8.15.0.59) with ESMTP id t2CN84Ub025090; Thu, 12 Mar 2015 18:08:04 -0500 Received: from white.natinst.com ([130.164.14.198]) by us-aus-mgwout1.amer.corp.natinst.com (Lotus Domino Release 8.5.3FP6) with ESMTP id 2015031218080493-341436 ; Thu, 12 Mar 2015 18:08:04 -0500 From: Jaeden Amero To: Nicolas Ferre , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jaeden Amero , Josh Cartwright , Soren Brinkmann Subject: [PATCH] net/macb: Only adjust tx_clk on link change Date: Thu, 12 Mar 2015 18:07:54 -0500 Message-Id: <1426201674-824-1-git-send-email-jaeden.amero@ni.com> X-Mailer: git-send-email 2.1.4 X-MIMETrack: Itemize by SMTP Server on US-AUS-MGWOut1/AUS/H/NIC(Release 8.5.3FP6|November 21, 2013) at 03/12/2015 06:08:04 PM, Serialize by Router on US-AUS-MGWOut1/AUS/H/NIC(Release 8.5.3FP6|November 21, 2013) at 03/12/2015 06:08:05 PM, Serialize complete at 03/12/2015 06:08:05 PM X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2015-03-12_08:, , signatures=0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The PHY state machine (in drivers/net/phy/phy.c) will unconditionally call phydev->adjust_link (macb_handle_link_change) when polling in the PHY_CHANGELINK state. As currently written, macb always ends up requesting a new tx_clk frequency in macb_handle_link_change. It is a waste of time to request a new tx_clk frequency if the link state hasn't changed, as the tx_clk will already be configured properly. Let's only request a new tx_clk clock frequency when necessary. Signed-off-by: Jaeden Amero Cc: Josh Cartwright Cc: Soren Brinkmann --- drivers/net/ethernet/cadence/macb.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c index f00be58..a0a04b3 100644 --- a/drivers/net/ethernet/cadence/macb.c +++ b/drivers/net/ethernet/cadence/macb.c @@ -293,10 +293,13 @@ static void macb_handle_link_change(struct net_device *dev) spin_unlock_irqrestore(&bp->lock, flags); - macb_set_tx_clk(bp->tx_clk, phydev->speed, dev); - if (status_change) { if (phydev->link) { + /* Update the TX clock rate if and only if the link is + * up and there has been a link change. + */ + macb_set_tx_clk(bp->tx_clk, phydev->speed, dev); + netif_carrier_on(dev); netdev_info(dev, "link up (%d/%s)\n", phydev->speed,