Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756906AbaKSUyD (ORCPT ); Wed, 19 Nov 2014 15:54:03 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:55888 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756688AbaKSUxv (ORCPT ); Wed, 19 Nov 2014 15:53:51 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Enric Balletbo i Serra , "David S. Miller" Subject: [PATCH 3.17 017/141] smsc911x: power-up phydev before doing a software reset. Date: Wed, 19 Nov 2014 12:50:40 -0800 Message-Id: <20141119205151.234335887@linuxfoundation.org> X-Mailer: git-send-email 2.1.3 In-Reply-To: <20141119205150.700188369@linuxfoundation.org> References: <20141119205150.700188369@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Enric Balletbo i Serra [ Upstream commit ccf899a27c08038db91765ff12bb0380dcd85887 ] With commit be9dad1f9f26604fb ("net: phy: suspend phydev when going to HALTED"), the PHY device will be put in a low-power mode using BMCR_PDOWN if the the interface is set down. The smsc911x driver does a software_reset opening the device driver (ndo_open). In such case, the PHY must be powered-up before access to any register and before calling the software_reset function. Otherwise, as the PHY is powered down the software reset fails and the interface can not be enabled again. This patch fixes this scenario that is easy to reproduce setting down the network interface and setting up again. $ ifconfig eth0 down $ ifconfig eth0 up ifconfig: SIOCSIFFLAGS: Input/output error Signed-off-by: Enric Balletbo i Serra Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/smsc/smsc911x.c | 46 +++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) --- a/drivers/net/ethernet/smsc/smsc911x.c +++ b/drivers/net/ethernet/smsc/smsc911x.c @@ -1342,6 +1342,42 @@ static void smsc911x_rx_multicast_update spin_unlock(&pdata->mac_lock); } +static int smsc911x_phy_general_power_up(struct smsc911x_data *pdata) +{ + int rc = 0; + + if (!pdata->phy_dev) + return rc; + + /* If the internal PHY is in General Power-Down mode, all, except the + * management interface, is powered-down and stays in that condition as + * long as Phy register bit 0.11 is HIGH. + * + * In that case, clear the bit 0.11, so the PHY powers up and we can + * access to the phy registers. + */ + rc = phy_read(pdata->phy_dev, MII_BMCR); + if (rc < 0) { + SMSC_WARN(pdata, drv, "Failed reading PHY control reg"); + return rc; + } + + /* If the PHY general power-down bit is not set is not necessary to + * disable the general power down-mode. + */ + if (rc & BMCR_PDOWN) { + rc = phy_write(pdata->phy_dev, MII_BMCR, rc & ~BMCR_PDOWN); + if (rc < 0) { + SMSC_WARN(pdata, drv, "Failed writing PHY control reg"); + return rc; + } + + usleep_range(1000, 1500); + } + + return 0; +} + static int smsc911x_phy_disable_energy_detect(struct smsc911x_data *pdata) { int rc = 0; @@ -1415,6 +1451,16 @@ static int smsc911x_soft_reset(struct sm int ret; /* + * Make sure to power-up the PHY chip before doing a reset, otherwise + * the reset fails. + */ + ret = smsc911x_phy_general_power_up(pdata); + if (ret) { + SMSC_WARN(pdata, drv, "Failed to power-up the PHY chip"); + return ret; + } + + /* * LAN9210/LAN9211/LAN9220/LAN9221 chips have an internal PHY that * are initialized in a Energy Detect Power-Down mode that prevents * the MAC chip to be software reseted. So we have to wakeup the PHY -- 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/