From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael Chan" Subject: [PATCH 3/3 net-next] tg3: Fix poor tx performance on 57766 after MTU change Date: Sun, 4 Mar 2012 16:48:15 -0800 Message-ID: <1330908495-3758-3-git-send-email-mchan@broadcom.com> References: <1330908495-3758-1-git-send-email-mchan@broadcom.com> <1330908495-3758-2-git-send-email-mchan@broadcom.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: davem@davemloft.net Return-path: Received: from mms3.broadcom.com ([216.31.210.19]:2532 "EHLO MMS3.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754963Ab2CEAkn (ORCPT ); Sun, 4 Mar 2012 19:40:43 -0500 In-Reply-To: <1330908495-3758-2-git-send-email-mchan@broadcom.com> Sender: netdev-owner@vger.kernel.org List-ID: GRC reset causes the read DMA engine to go into a mode that breaks up requests into 256 bytes. A PHY reset is required to bring it back to the normal mode. Signed-off-by: Michael Chan --- drivers/net/ethernet/broadcom/tg3.c | 10 ++++++++-- 1 files changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index 0da93db..a8490a4 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -12267,7 +12267,7 @@ static inline void tg3_set_mtu(struct net_device *dev, struct tg3 *tp, static int tg3_change_mtu(struct net_device *dev, int new_mtu) { struct tg3 *tp = netdev_priv(dev); - int err; + int err, reset_phy = 0; if (new_mtu < TG3_MIN_MTU || new_mtu > TG3_MAX_MTU(tp)) return -EINVAL; @@ -12290,7 +12290,13 @@ static int tg3_change_mtu(struct net_device *dev, int new_mtu) tg3_set_mtu(dev, tp, new_mtu); - err = tg3_restart_hw(tp, 0); + /* Reset PHY, otherwise the read DMA engine will be in a mode that + * breaks all requests to 256 bytes. + */ + if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_57766) + reset_phy = 1; + + err = tg3_restart_hw(tp, reset_phy); if (!err) tg3_netif_start(tp); -- 1.7.1