diff options
| -rw-r--r-- | drivers/net/dsa/microchip/ksz8795.c | 70 | ||||
| -rw-r--r-- | drivers/net/dsa/microchip/ksz_common.c | 4 | ||||
| -rw-r--r-- | drivers/net/dsa/microchip/ksz_common.h | 1 |
3 files changed, 74 insertions, 1 deletions
diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c index 88b10aa527d6..ec1ddfcf7473 100644 --- a/drivers/net/dsa/microchip/ksz8795.c +++ b/drivers/net/dsa/microchip/ksz8795.c @@ -1440,6 +1440,74 @@ void ksz8_config_cpu_port(struct dsa_switch *ds) } /** + * ksz8_phy_port_link_up - Configures ports with integrated PHYs + * @dev: The KSZ device instance. + * @port: The port number to configure. + * @duplex: The desired duplex mode. + * @tx_pause: If true, enables transmit pause. + * @rx_pause: If true, enables receive pause. + * + * Description: + * The function configures flow control settings for a given port based on the + * desired settings and current duplex mode. + * + * According to the KSZ8873 datasheet, the PORT_FORCE_FLOW_CTRL bit in the + * Port Control 2 register (0x1A for Port 1, 0x22 for Port 2, 0x32 for Port 3) + * determines how flow control is handled on the port: + * "1 = will always enable full-duplex flow control on the port, regardless + * of AN result. + * 0 = full-duplex flow control is enabled based on AN result." + * + * This means that the flow control behavior depends on the state of this bit: + * - If PORT_FORCE_FLOW_CTRL is set to 1, the switch will ignore AN results and + * force flow control on the port. + * - If PORT_FORCE_FLOW_CTRL is set to 0, the switch will enable or disable + * flow control based on the AN results. + * + * However, there is a potential limitation in this configuration. It is + * currently not possible to force disable flow control on a port if we still + * advertise pause support. While such a configuration is not currently + * supported by Linux, and may not make practical sense, it's important to be + * aware of this limitation when working with the KSZ8873 and similar devices. + */ +static void ksz8_phy_port_link_up(struct ksz_device *dev, int port, int duplex, + bool tx_pause, bool rx_pause) +{ + const u16 *regs = dev->info->regs; + u8 sctrl = 0; + + /* The KSZ8795 switch differs from the KSZ8873 by supporting + * asymmetric pause control. However, since a single bit is used to + * control both RX and TX pause, we can't enforce asymmetric pause + * control - both TX and RX pause will be either enabled or disabled + * together. + * + * If auto-negotiation is enabled, we usually allow the flow control to + * be determined by the auto-negotiation process based on the + * capabilities of both link partners. However, for KSZ8873, the + * PORT_FORCE_FLOW_CTRL bit may be set by the hardware bootstrap, + * ignoring the auto-negotiation result. Thus, even in auto-negotiation + * mode, we need to ensure that the PORT_FORCE_FLOW_CTRL bit is + * properly cleared. + * + * In the absence of pause auto-negotiation, we will enforce symmetric + * pause control for both variants of switches - KSZ8873 and KSZ8795. + * + * Autoneg Pause Autoneg rx,tx PORT_FORCE_FLOW_CTRL + * 1 1 x 0 + * 0 1 x 0 (flow control probably disabled) + * x 0 1 1 (flow control force enabled) + * 1 0 0 0 (flow control still depends on + * aneg result due to hardware) + * 0 0 0 0 (flow control probably disabled) + */ + if (dev->ports[port].manual_flow && tx_pause) + sctrl |= PORT_FORCE_FLOW_CTRL; + + ksz_prmw8(dev, port, regs[P_STP_CTRL], PORT_FORCE_FLOW_CTRL, sctrl); +} + +/** * ksz8_cpu_port_link_up - Configures the CPU port of the switch. * @dev: The KSZ device instance. * @speed: The desired link speed. @@ -1488,6 +1556,8 @@ void ksz8_phylink_mac_link_up(struct ksz_device *dev, int port, */ if (dev->cpu_port == port) ksz8_cpu_port_link_up(dev, speed, duplex, tx_pause, rx_pause); + else if (dev->info->internal_phy[port]) + ksz8_phy_port_link_up(dev, port, duplex, tx_pause, rx_pause); } static int ksz8_handle_global_errata(struct dsa_switch *ds) diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c index 0ee7cfb8d4bd..3b1fe9aff6a8 100644 --- a/drivers/net/dsa/microchip/ksz_common.c +++ b/drivers/net/dsa/microchip/ksz_common.c @@ -2967,8 +2967,10 @@ static void ksz_phylink_mac_config(struct dsa_switch *ds, int port, { struct ksz_device *dev = ds->priv; - if (ksz_is_ksz88x3(dev)) + if (ksz_is_ksz88x3(dev)) { + dev->ports[port].manual_flow = !(state->pause & MLO_PAUSE_AN); return; + } /* Internal PHYs */ if (dev->info->internal_phy[port]) diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h index b7e8a403a132..d1a1c876ba0d 100644 --- a/drivers/net/dsa/microchip/ksz_common.h +++ b/drivers/net/dsa/microchip/ksz_common.h @@ -134,6 +134,7 @@ struct ksz_port { ktime_t tstamp_msg; struct completion tstamp_msg_comp; #endif + bool manual_flow; }; struct ksz_device { |