Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754675AbbK0OAY (ORCPT ); Fri, 27 Nov 2015 09:00:24 -0500 Received: from mail.karo-electronics.de ([81.173.242.67]:63247 "EHLO mail.karo-electronics.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754596AbbK0OAW (ORCPT ); Fri, 27 Nov 2015 09:00:22 -0500 X-Greylist: delayed 1082 seconds by postgrey-1.27 at vger.kernel.org; Fri, 27 Nov 2015 09:00:21 EST From: =?UTF-8?q?Lothar=20Wa=C3=9Fmann?= To: Andrew Lunn , "David S. Miller" , Fabio Estevam , Kevin Hao , =?UTF-8?q?Lothar=20Wa=C3=9Fmann?= , Lucas Stach , Nimrod Andy , Philippe Reynes , Russell King , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Stefan Agner Subject: [PATCH] net: fec: fix enet_out clock handling Date: Fri, 27 Nov 2015 14:39:10 +0100 Message-Id: <1448631550-943-1-git-send-email-LW@KARO-electronics.de> X-Mailer: git-send-email 2.1.4 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3537 Lines: 113 When ENET_OUT is being used as reference clock for an external PHY, the clock must not be disabled while the PHY is active. Otherwise the PHY may lose its internal state and require a reset to become functional again. A symptom for this bug is a network interface that constantly toggles between UP and DOWN state: fec 800f0000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx fec 800f0000.ethernet eth0: Link is Down fec 800f0000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx fec 800f0000.ethernet eth0: Link is Down [...] Signed-off-by: Lothar Waßmann --- drivers/net/ethernet/freescale/fec_main.c | 34 +++++++++++++------------------ 1 file changed, 14 insertions(+), 20 deletions(-) diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index d2328fc..d9df4c5 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -1857,11 +1857,6 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable) ret = clk_prepare_enable(fep->clk_ahb); if (ret) return ret; - if (fep->clk_enet_out) { - ret = clk_prepare_enable(fep->clk_enet_out); - if (ret) - goto failed_clk_enet_out; - } if (fep->clk_ptp) { mutex_lock(&fep->ptp_clk_mutex); ret = clk_prepare_enable(fep->clk_ptp); @@ -1873,35 +1868,26 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable) } mutex_unlock(&fep->ptp_clk_mutex); } - if (fep->clk_ref) { - ret = clk_prepare_enable(fep->clk_ref); - if (ret) - goto failed_clk_ref; - } + ret = clk_prepare_enable(fep->clk_ref); + if (ret) + goto failed_clk_ref; } else { clk_disable_unprepare(fep->clk_ahb); - if (fep->clk_enet_out) - clk_disable_unprepare(fep->clk_enet_out); if (fep->clk_ptp) { mutex_lock(&fep->ptp_clk_mutex); clk_disable_unprepare(fep->clk_ptp); fep->ptp_clk_on = false; mutex_unlock(&fep->ptp_clk_mutex); } - if (fep->clk_ref) - clk_disable_unprepare(fep->clk_ref); + clk_disable_unprepare(fep->clk_ref); } return 0; failed_clk_ref: - if (fep->clk_ref) - clk_disable_unprepare(fep->clk_ref); + clk_disable_unprepare(fep->clk_ref); failed_clk_ptp: - if (fep->clk_enet_out) - clk_disable_unprepare(fep->clk_enet_out); -failed_clk_enet_out: - clk_disable_unprepare(fep->clk_ahb); + clk_disable_unprepare(fep->clk_ahb); return ret; } @@ -3425,6 +3411,10 @@ fec_probe(struct platform_device *pdev) if (ret) goto failed_clk; + ret = clk_prepare_enable(fep->clk_enet_out); + if (ret) + goto failed_clk_enet_out; + ret = clk_prepare_enable(fep->clk_ipg); if (ret) goto failed_clk_ipg; @@ -3509,6 +3499,8 @@ failed_init: if (fep->reg_phy) regulator_disable(fep->reg_phy); failed_regulator: + clk_disable_unprepare(fep->clk_enet_out); +failed_clk_enet_out: clk_disable_unprepare(fep->clk_ipg); failed_clk_ipg: fec_enet_clk_enable(ndev, false); @@ -3531,6 +3523,8 @@ fec_drv_remove(struct platform_device *pdev) fec_ptp_stop(pdev); unregister_netdev(ndev); fec_enet_mii_remove(fep); + fec_enet_clk_enable(ndev, false); + clk_disable_unprepare(fep->clk_enet_out); if (fep->reg_phy) regulator_disable(fep->reg_phy); of_node_put(fep->phy_node); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/