From 3a55402c93877d291b0a612d25edb03d1b4b93ac Mon Sep 17 00:00:00 2001 From: Doug Berger Date: Tue, 5 Nov 2019 11:07:24 -0800 Subject: net: bcmgenet: use RGMII loopback for MAC reset As noted in commit 28c2d1a7a0bf ("net: bcmgenet: enable loopback during UniMAC sw_reset") the UniMAC must be clocked while sw_reset is asserted for its state machines to reset cleanly. The transmit and receive clocks used by the UniMAC are derived from the signals used on its PHY interface. The bcmgenet MAC can be configured to work with different PHY interfaces including MII, GMII, RGMII, and Reverse MII on internal and external interfaces. Unfortunately for the UniMAC, when configured for MII the Tx clock is always driven from the PHY which places it outside of the direct control of the MAC. The earlier commit enabled a local loopback mode within the UniMAC so that the receive clock would be derived from the transmit clock which addressed the observed issue with an external GPHY disabling it's Rx clock. However, when a Tx clock is not available this loopback is insufficient. This commit implements a workaround that leverages the fact that the MAC can reliably generate all of its necessary clocking by enterring the external GPHY RGMII interface mode with the UniMAC in local loopback during the sw_reset interval. Unfortunately, this has the undesirable side efect of the RGMII GTXCLK signal being driven during the same window. In most configurations this is a benign side effect as the signal is either not routed to a pin or is already expected to drive the pin. The one exception is when an external MII PHY is expected to drive the same pin with its TX_CLK output creating output driver contention. This commit exploits the IEEE 802.3 clause 22 standard defined isolate mode to force an external MII PHY to present a high impedance on its TX_CLK output during the window to prevent any contention at the pin. The MII interface is used internally with the 40nm internal EPHY which agressively disables its clocks for power savings leading to incomplete resets of the UniMAC and many instabilities observed over the years. The workaround of this commit is expected to put an end to those problems. Fixes: 1c1008c793fa ("net: bcmgenet: add main driver file") Signed-off-by: Doug Berger Acked-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/genet/bcmmii.c | 33 ++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'drivers/net/ethernet/broadcom/genet/bcmmii.c') diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c index 17bb8d60a157..fcd181ae3a7d 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmmii.c +++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c @@ -221,8 +221,38 @@ int bcmgenet_mii_config(struct net_device *dev, bool init) const char *phy_name = NULL; u32 id_mode_dis = 0; u32 port_ctrl; + int bmcr = -1; + int ret; u32 reg; + /* MAC clocking workaround during reset of umac state machines */ + reg = bcmgenet_umac_readl(priv, UMAC_CMD); + if (reg & CMD_SW_RESET) { + /* An MII PHY must be isolated to prevent TXC contention */ + if (priv->phy_interface == PHY_INTERFACE_MODE_MII) { + ret = phy_read(phydev, MII_BMCR); + if (ret >= 0) { + bmcr = ret; + ret = phy_write(phydev, MII_BMCR, + bmcr | BMCR_ISOLATE); + } + if (ret) { + netdev_err(dev, "failed to isolate PHY\n"); + return ret; + } + } + /* Switch MAC clocking to RGMII generated clock */ + bcmgenet_sys_writel(priv, PORT_MODE_EXT_GPHY, SYS_PORT_CTRL); + /* Ensure 5 clks with Rx disabled + * followed by 5 clks with Reset asserted + */ + udelay(4); + reg &= ~(CMD_SW_RESET | CMD_LCL_LOOP_EN); + bcmgenet_umac_writel(priv, reg, UMAC_CMD); + /* Ensure 5 more clocks before Rx is enabled */ + udelay(2); + } + priv->ext_phy = !priv->internal_phy && (priv->phy_interface != PHY_INTERFACE_MODE_MOCA); @@ -254,6 +284,9 @@ int bcmgenet_mii_config(struct net_device *dev, bool init) phy_set_max_speed(phydev, SPEED_100); bcmgenet_sys_writel(priv, PORT_MODE_EXT_EPHY, SYS_PORT_CTRL); + /* Restore the MII PHY after isolation */ + if (bmcr >= 0) + phy_write(phydev, MII_BMCR, bmcr); break; case PHY_INTERFACE_MODE_REVMII: -- cgit v1.2.3-59-g8ed1b From 6b6d017fccb4693767d2fcae9ef2fd05243748bb Mon Sep 17 00:00:00 2001 From: Doug Berger Date: Tue, 5 Nov 2019 11:07:25 -0800 Subject: Revert "net: bcmgenet: soft reset 40nm EPHYs before MAC init" This reverts commit 1f515486275a08a17a2c806b844cca18f7de5b34. This commit improved the chances of the umac resetting cleanly by ensuring that the PHY was restored to its normal operation prior to resetting the umac. However, there were still cases when the PHY might not be driving a Tx clock to the umac during this window (e.g. when the PHY detects no link). The previous commit now ensures that the unimac receives clocks from the MAC during its reset window so this commit is no longer needed. This commit also has an unintended negative impact on the MDIO performance of the UniMAC MDIO interface because it is used before the MDIO interrupts are reenabled, so it should be removed. Signed-off-by: Doug Berger Acked-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/genet/bcmgenet.c | 28 +++---- drivers/net/ethernet/broadcom/genet/bcmgenet.h | 2 +- drivers/net/ethernet/broadcom/genet/bcmmii.c | 112 ++++++++++++++----------- 3 files changed, 73 insertions(+), 69 deletions(-) (limited to 'drivers/net/ethernet/broadcom/genet/bcmmii.c') diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c index a1776ed8d7a1..b5255dd08265 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c @@ -2877,12 +2877,6 @@ static int bcmgenet_open(struct net_device *dev) if (priv->internal_phy) bcmgenet_power_up(priv, GENET_POWER_PASSIVE); - ret = bcmgenet_mii_connect(dev); - if (ret) { - netdev_err(dev, "failed to connect to PHY\n"); - goto err_clk_disable; - } - /* take MAC out of reset */ bcmgenet_umac_reset(priv); @@ -2892,12 +2886,6 @@ static int bcmgenet_open(struct net_device *dev) reg = bcmgenet_umac_readl(priv, UMAC_CMD); priv->crc_fwd_en = !!(reg & CMD_CRC_FWD); - ret = bcmgenet_mii_config(dev, true); - if (ret) { - netdev_err(dev, "unsupported PHY\n"); - goto err_disconnect_phy; - } - bcmgenet_set_hw_addr(priv, dev->dev_addr); if (priv->internal_phy) { @@ -2913,7 +2901,7 @@ static int bcmgenet_open(struct net_device *dev) ret = bcmgenet_init_dma(priv); if (ret) { netdev_err(dev, "failed to initialize DMA\n"); - goto err_disconnect_phy; + goto err_clk_disable; } /* Always enable ring 16 - descriptor ring */ @@ -2936,19 +2924,25 @@ static int bcmgenet_open(struct net_device *dev) goto err_irq0; } + ret = bcmgenet_mii_probe(dev); + if (ret) { + netdev_err(dev, "failed to connect to PHY\n"); + goto err_irq1; + } + bcmgenet_netif_start(dev); netif_tx_start_all_queues(dev); return 0; +err_irq1: + free_irq(priv->irq1, priv); err_irq0: free_irq(priv->irq0, priv); err_fini_dma: bcmgenet_dma_teardown(priv); bcmgenet_fini_dma(priv); -err_disconnect_phy: - phy_disconnect(dev->phydev); err_clk_disable: if (priv->internal_phy) bcmgenet_power_down(priv, GENET_POWER_PASSIVE); @@ -3629,8 +3623,6 @@ static int bcmgenet_resume(struct device *d) if (priv->internal_phy) bcmgenet_power_up(priv, GENET_POWER_PASSIVE); - phy_init_hw(dev->phydev); - bcmgenet_umac_reset(priv); init_umac(priv); @@ -3639,6 +3631,8 @@ static int bcmgenet_resume(struct device *d) if (priv->wolopts) clk_disable_unprepare(priv->clk_wol); + phy_init_hw(dev->phydev); + /* Speed settings must be restored */ bcmgenet_mii_config(priv->dev, false); diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.h b/drivers/net/ethernet/broadcom/genet/bcmgenet.h index 7fbf573d8d52..dbc69d8fa05f 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.h +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.h @@ -720,8 +720,8 @@ GENET_IO_MACRO(rbuf, GENET_RBUF_OFF); /* MDIO routines */ int bcmgenet_mii_init(struct net_device *dev); -int bcmgenet_mii_connect(struct net_device *dev); int bcmgenet_mii_config(struct net_device *dev, bool init); +int bcmgenet_mii_probe(struct net_device *dev); void bcmgenet_mii_exit(struct net_device *dev); void bcmgenet_phy_power_set(struct net_device *dev, bool enable); void bcmgenet_mii_setup(struct net_device *dev); diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c index fcd181ae3a7d..dbe18cdf6c1b 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmmii.c +++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c @@ -173,46 +173,6 @@ static void bcmgenet_moca_phy_setup(struct bcmgenet_priv *priv) bcmgenet_fixed_phy_link_update); } -int bcmgenet_mii_connect(struct net_device *dev) -{ - struct bcmgenet_priv *priv = netdev_priv(dev); - struct device_node *dn = priv->pdev->dev.of_node; - struct phy_device *phydev; - u32 phy_flags = 0; - int ret; - - /* Communicate the integrated PHY revision */ - if (priv->internal_phy) - phy_flags = priv->gphy_rev; - - /* Initialize link state variables that bcmgenet_mii_setup() uses */ - priv->old_link = -1; - priv->old_speed = -1; - priv->old_duplex = -1; - priv->old_pause = -1; - - if (dn) { - phydev = of_phy_connect(dev, priv->phy_dn, bcmgenet_mii_setup, - phy_flags, priv->phy_interface); - if (!phydev) { - pr_err("could not attach to PHY\n"); - return -ENODEV; - } - } else { - phydev = dev->phydev; - phydev->dev_flags = phy_flags; - - ret = phy_connect_direct(dev, phydev, bcmgenet_mii_setup, - priv->phy_interface); - if (ret) { - pr_err("could not attach to PHY\n"); - return -ENODEV; - } - } - - return 0; -} - int bcmgenet_mii_config(struct net_device *dev, bool init) { struct bcmgenet_priv *priv = netdev_priv(dev); @@ -339,21 +299,71 @@ int bcmgenet_mii_config(struct net_device *dev, bool init) bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL); } - if (init) { - linkmode_copy(phydev->advertising, phydev->supported); + if (init) + dev_info(kdev, "configuring instance for %s\n", phy_name); - /* The internal PHY has its link interrupts routed to the - * Ethernet MAC ISRs. On GENETv5 there is a hardware issue - * that prevents the signaling of link UP interrupts when - * the link operates at 10Mbps, so fallback to polling for - * those versions of GENET. - */ - if (priv->internal_phy && !GENET_IS_V5(priv)) - phydev->irq = PHY_IGNORE_INTERRUPT; + return 0; +} - dev_info(kdev, "configuring instance for %s\n", phy_name); +int bcmgenet_mii_probe(struct net_device *dev) +{ + struct bcmgenet_priv *priv = netdev_priv(dev); + struct device_node *dn = priv->pdev->dev.of_node; + struct phy_device *phydev; + u32 phy_flags = 0; + int ret; + + /* Communicate the integrated PHY revision */ + if (priv->internal_phy) + phy_flags = priv->gphy_rev; + + /* Initialize link state variables that bcmgenet_mii_setup() uses */ + priv->old_link = -1; + priv->old_speed = -1; + priv->old_duplex = -1; + priv->old_pause = -1; + + if (dn) { + phydev = of_phy_connect(dev, priv->phy_dn, bcmgenet_mii_setup, + phy_flags, priv->phy_interface); + if (!phydev) { + pr_err("could not attach to PHY\n"); + return -ENODEV; + } + } else { + phydev = dev->phydev; + phydev->dev_flags = phy_flags; + + ret = phy_connect_direct(dev, phydev, bcmgenet_mii_setup, + priv->phy_interface); + if (ret) { + pr_err("could not attach to PHY\n"); + return -ENODEV; + } + } + + /* Configure port multiplexer based on what the probed PHY device since + * reading the 'max-speed' property determines the maximum supported + * PHY speed which is needed for bcmgenet_mii_config() to configure + * things appropriately. + */ + ret = bcmgenet_mii_config(dev, true); + if (ret) { + phy_disconnect(dev->phydev); + return ret; } + linkmode_copy(phydev->advertising, phydev->supported); + + /* The internal PHY has its link interrupts routed to the + * Ethernet MAC ISRs. On GENETv5 there is a hardware issue + * that prevents the signaling of link UP interrupts when + * the link operates at 10Mbps, so fallback to polling for + * those versions of GENET. + */ + if (priv->internal_phy && !GENET_IS_V5(priv)) + dev->phydev->irq = PHY_IGNORE_INTERRUPT; + return 0; } -- cgit v1.2.3-59-g8ed1b