Changing the netif_carrier_*() state behind phylink's back has always been prohibited because it messes up with phylinks state tracking, and means that phylink no longer guarantees to call the mac_link_down() and mac_link_up() methods at the appropriate times. This was later documented in the sfp-phylink network driver conversion guide. stmmac was converted to phylink in 2019, but nothing was done with the "PCS" code. Since then, apart from the updates as part of phylink development, nothing has happened with stmmac to improve its use of phylink, or even to address this point. A couple of years ago, a has_integrated_pcs boolean was added by Bart, which later became the STMMAC_FLAG_HAS_INTEGRATED_PCS flag, to avoid manipulating the netif_carrier_*() state. This flag is mis-named, because whenever the stmmac is synthesized for its native SGMII, TBI or RTBI interfaces, it has an "integrated PCS". This boolean/flag actually means "ignore the status from the integrated PCS". Discussing with Bart, the reasons for this are lost to the winds of time (which is why we should always document the reasons in the commit message.) RGMII also has in-band status, and the dwmac cores and stmmac code supports this but with one bug that saves the day. When dwmac cores are synthesised for RGMII only, they do not contain an integrated PCS, and so priv->dma_cap.pcs is clear, which prevents (incorrectly) the "RGMII PCS" being used, meaning we don't read the in-band status. However, a core synthesised for RGMII and also SGMII, TBI or RTBI will have this capability bit set, thus making these code paths reachable. The Jetson Xavier NX uses RGMII mode to talk to its PHY, and removing the incorrect check for priv->dma_cap.pcs reveals the theortical issue with netif_carrier_*() manipulation is real: dwc-eth-dwmac 2490000.ethernet eth0: Register MEM_TYPE_PAGE_POOL RxQ-0 dwc-eth-dwmac 2490000.ethernet eth0: PHY [stmmac-0:00] driver [RTL8211F Gigabit Ethernet] (irq=141) dwc-eth-dwmac 2490000.ethernet eth0: No Safety Features support found dwc-eth-dwmac 2490000.ethernet eth0: IEEE 1588-2008 Advanced Timestamp supported dwc-eth-dwmac 2490000.ethernet eth0: registered PTP clock dwc-eth-dwmac 2490000.ethernet eth0: configuring for phy/rgmii-id link mode 8021q: adding VLAN 0 to HW filter on device eth0 dwc-eth-dwmac 2490000.ethernet eth0: Adding VLAN ID 0 is not supported Link is Up - 1000/Full Link is Down Link is Up - 1000/Full This looks good until one realises that the phylink "Link" status messages are missing, even when the RJ45 cable is reconnected. Nothing one can do results in the interface working. The interrupt handler (which prints those "Link is" messages) always wins over phylink's resolve worker, meaning phylink never calls the mac_link_up() nor mac_link_down() methods. eth0 also sees no traffic received, and is unable to obtain a DHCP address: 3: eth0: mtu 1500 qdisc mq state UP group defa ult qlen 1000 link/ether e6:d3:6a:e6:92:de brd ff:ff:ff:ff:ff:ff RX: bytes packets errors dropped overrun mcast 0 0 0 0 0 0 TX: bytes packets errors dropped carrier collsns 27686 149 0 0 0 0 With the STMMAC_FLAG_HAS_INTEGRATED_PCS flag set, which disables the netif_carrier_*() manipulation then stmmac works normally: dwc-eth-dwmac 2490000.ethernet eth0: Register MEM_TYPE_PAGE_POOL RxQ-0 dwc-eth-dwmac 2490000.ethernet eth0: PHY [stmmac-0:00] driver [RTL8211F Gigabit Ethernet] (irq=141) dwc-eth-dwmac 2490000.ethernet eth0: No Safety Features support found dwc-eth-dwmac 2490000.ethernet eth0: IEEE 1588-2008 Advanced Timestamp supported dwc-eth-dwmac 2490000.ethernet eth0: registered PTP clock dwc-eth-dwmac 2490000.ethernet eth0: configuring for phy/rgmii-id link mode 8021q: adding VLAN 0 to HW filter on device eth0 dwc-eth-dwmac 2490000.ethernet eth0: Adding VLAN ID 0 is not supported Link is Up - 1000/Full dwc-eth-dwmac 2490000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx and packets can be transferred. This clearly shows that when priv->hw->pcs is set, but STMMAC_FLAG_HAS_INTEGRATED_PCS is clear, the driver reliably fails. Discovering whether a platform falls into this is impossible as parsing all the dtsi and dts files to find out which use the stmmac driver, whether any of them use RGMII or SGMII and also depends whether an external interface is being used. The kernel likely doesn't contain all dts files either. The only driver that sets this flag uses the qcom,sa8775p-ethqos compatible, and uses SGMII or 2500BASE-X. but these are saved from this problem by the incorrect check for priv->dma_cap.pcs. So, we have to assume that for every other platform that uses SGMII with stmmac is using an external PCS. Moreover, ethtool output can be incorrect. With the full-duplex link negotiated, ethtool reports: Speed: 1000Mb/s Duplex: Half because with dwmac4, the full-duplex bit is in bit 16 of the status, priv->xstats.pcs_duplex becomes BIT(16) for full duplex, but the ethtool ksettings duplex member is u8 - so becomes zero. Moreover, the supported, advertised and link partner modes are all "not reported". Finally, ksettings_set() won't be able to set the advertisement on a PHY if this PCS code is activated, which is incorrect when SGMII is used with a PHY. Thus, remove: 1. the incorrect netif_carrier_*() manipulation. 2. the broken ethtool ksettings code. Given that all uses of STMMAC_FLAG_HAS_INTEGRATED_PCS are now gone, remove the flag from stmmac.h and dwmac-qcom-ethqos.c. Signed-off-by: Russell King (Oracle) --- .../stmicro/stmmac/dwmac-qcom-ethqos.c | 4 -- .../ethernet/stmicro/stmmac/stmmac_ethtool.c | 55 ------------------- .../net/ethernet/stmicro/stmmac/stmmac_main.c | 9 --- include/linux/stmmac.h | 1 - 4 files changed, 69 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c index d8fd4d8f6ced..f62825220cf7 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c @@ -96,7 +96,6 @@ struct ethqos_emac_driver_data { bool rgmii_config_loopback_en; bool has_emac_ge_3; const char *link_clk_name; - bool has_integrated_pcs; u32 dma_addr_width; struct dwmac4_addrs dwmac4_addrs; bool needs_sgmii_loopback; @@ -282,7 +281,6 @@ static const struct ethqos_emac_driver_data emac_v4_0_0_data = { .rgmii_config_loopback_en = false, .has_emac_ge_3 = true, .link_clk_name = "phyaux", - .has_integrated_pcs = true, .needs_sgmii_loopback = true, .dma_addr_width = 36, .dwmac4_addrs = { @@ -856,8 +854,6 @@ static int qcom_ethqos_probe(struct platform_device *pdev) plat_dat->flags |= STMMAC_FLAG_TSO_EN; if (of_device_is_compatible(np, "qcom,qcs404-ethqos")) plat_dat->flags |= STMMAC_FLAG_RX_CLK_RUNS_IN_LPI; - if (data->has_integrated_pcs) - plat_dat->flags |= STMMAC_FLAG_HAS_INTEGRATED_PCS; if (data->dma_addr_width) plat_dat->host_dma_width = data->dma_addr_width; diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c index 39fa1ec92f82..d89662b48087 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c @@ -322,47 +322,6 @@ static int stmmac_ethtool_get_link_ksettings(struct net_device *dev, { struct stmmac_priv *priv = netdev_priv(dev); - if (!(priv->plat->flags & STMMAC_FLAG_HAS_INTEGRATED_PCS) && - (priv->hw->pcs & STMMAC_PCS_RGMII || - priv->hw->pcs & STMMAC_PCS_SGMII)) { - u32 supported, advertising, lp_advertising; - - if (!priv->xstats.pcs_link) { - cmd->base.speed = SPEED_UNKNOWN; - cmd->base.duplex = DUPLEX_UNKNOWN; - return 0; - } - cmd->base.duplex = priv->xstats.pcs_duplex; - - cmd->base.speed = priv->xstats.pcs_speed; - - /* Encoding of PSE bits is defined in 802.3z, 37.2.1.4 */ - - ethtool_convert_link_mode_to_legacy_u32( - &supported, cmd->link_modes.supported); - ethtool_convert_link_mode_to_legacy_u32( - &advertising, cmd->link_modes.advertising); - ethtool_convert_link_mode_to_legacy_u32( - &lp_advertising, cmd->link_modes.lp_advertising); - - /* Reg49[3] always set because ANE is always supported */ - cmd->base.autoneg = ADVERTISED_Autoneg; - supported |= SUPPORTED_Autoneg; - advertising |= ADVERTISED_Autoneg; - lp_advertising |= ADVERTISED_Autoneg; - - cmd->base.port = PORT_OTHER; - - ethtool_convert_legacy_u32_to_link_mode( - cmd->link_modes.supported, supported); - ethtool_convert_legacy_u32_to_link_mode( - cmd->link_modes.advertising, advertising); - ethtool_convert_legacy_u32_to_link_mode( - cmd->link_modes.lp_advertising, lp_advertising); - - return 0; - } - return phylink_ethtool_ksettings_get(priv->phylink, cmd); } @@ -372,20 +331,6 @@ stmmac_ethtool_set_link_ksettings(struct net_device *dev, { struct stmmac_priv *priv = netdev_priv(dev); - if (!(priv->plat->flags & STMMAC_FLAG_HAS_INTEGRATED_PCS) && - (priv->hw->pcs & STMMAC_PCS_RGMII || - priv->hw->pcs & STMMAC_PCS_SGMII)) { - /* Only support ANE */ - if (cmd->base.autoneg != AUTONEG_ENABLE) - return -EINVAL; - - mutex_lock(&priv->lock); - stmmac_pcs_ctrl_ane(priv, 1, priv->hw->ps, 0); - mutex_unlock(&priv->lock); - - return 0; - } - return phylink_ethtool_ksettings_set(priv->phylink, cmd); } diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index d17820d9e7f1..194d17beec99 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -6030,15 +6030,6 @@ static void stmmac_common_interrupt(struct stmmac_priv *priv) for (queue = 0; queue < queues_count; queue++) stmmac_host_mtl_irq_status(priv, priv->hw, queue); - /* PCS link status */ - if (priv->hw->pcs && - !(priv->plat->flags & STMMAC_FLAG_HAS_INTEGRATED_PCS)) { - if (priv->xstats.pcs_link) - netif_carrier_on(priv->dev); - else - netif_carrier_off(priv->dev); - } - stmmac_timestamp_interrupt(priv, priv); } } diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h index fa1318bac06c..99022620457a 100644 --- a/include/linux/stmmac.h +++ b/include/linux/stmmac.h @@ -171,7 +171,6 @@ struct dwmac4_addrs { u32 mtl_low_cred_offset; }; -#define STMMAC_FLAG_HAS_INTEGRATED_PCS BIT(0) #define STMMAC_FLAG_SPH_DISABLE BIT(1) #define STMMAC_FLAG_USE_PHY_WOL BIT(2) #define STMMAC_FLAG_HAS_SUN8I BIT(3) -- 2.47.3