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所属分类：linux技术
PHY的12种状态
enum phy_state { PHY_DOWN = 0, //关闭网卡 PHY_STARTING, //PHY设备准备好了，PHY driver尚为准备好 PHY_READY, //PHY设备注册成功 PHY_PENDING, //PHY芯片挂起 PHY_UP, //开启网卡 PHY_AN, //网卡自协商 PHY_RUNNING, //网卡已经插入网线并建立物理连接，该状态可切换到PHY_CHANGELINK PHY_NOLINK, //断网，拔掉网线 PHY_FORCING,//自动协商失败，强制处理（读phy状态寄存器，设置速率，设置工作模式） PHY_CHANGELINK, //LINK检查，当物理连接存在时切换到PHY_RUNING，物理连接不存在时切换到PHY_NOLINK PHY_HALTED, //网卡关闭时，PHY挂起 PHY_RESUMING //网卡开启时，PHY恢复 }; PHY状态机
PHY指PHY芯片，负责数据传送与接收所需要的电与光信号、线路状态、时钟基准、数据编码和电路等,并向数据链路层设备提供标准接口。
MAC指MAC芯片，属于数据链路层，提供寻址机构、数据帧的构建、数据差错检查、传送控制、向网络层提供标准的数据接口等功能。
PHY_DOWN: phy、phy driver、mac都没准备好
- 如果phy driver被集成在内核中，PHY.probe后，phydev状态为PHY_READY。
- 如果phy driver被未集成在内核中，PHY.probe后，phydev状态为PHY_STARTING。
PHY_READY：phy、phy driver已经就绪，mac未准备好
当MAC层加载时，在PHY.start后，phydev状态切换为PHY_UP。
PHY_STARTING：phy准备就绪，phy driver、mac未准备好
- 当MAC加载时，PHY.start后，phydev状态为PHY_PENDING。
- 当phy driver加载时，phydev状态为PHY_READY。
PHY_PENDING：phy、mac准备就绪,phy driver未准备好
当phy dirver加载后，phdev状态为PHY_UP
上图中0-->1-->2-->4、0-->2-->4代表phy、phy dirver、mac顺序加载。
0-->1-->3-->4代表phy、mac、phy driver顺序加载。
PHY_UP：phy、phy driver、mac准备就绪
当前状态将启动自动协商，若启动成功则进入PHY_AN，若启动失败则进入PHY_FORCING。
PHY_AN：网卡自协商模式，检测自协商是否完成。
先判断物理链路的状态，如果未LINK则进入PHY_NOLINK，如果LINK则判断自协商是否完成，
自协商完成进入PHY_RUNNING，若自协商超时则重新开启自协商。
PHY_FORCING：强制协商
读link和自协商状态寄存器，如果状态正常则进入PHY_RUNNING模式。
PHY_NOLINK：物理链路未连接
判断物理链路状态，如果LINK，再判断是否支持自协商，若支持待自协商完成后进入PHY_RUNNING模式，
若不支持，直接进入PHY_RUNNING模式。若自协商处于挂起状态，则进入PHY_AN模式。
PHY_RUNNING：正常运行中
获取当前link状态，当link状态发生改变时，进入PHY_CHANGELINK模式。
PHY_CHANGELINK：检查物理链路
物理链路link时，切换到PHY_RUNNING，非LINK时切换到PHY_NOLINK。
PHY_HALTED：网卡关闭phy_stop
挂起phy
PHY_RESUMING: 网卡启用phy_start
恢复phy
phy_state_machine是PHY的状态机函数
/** * phy_state_machine - Handle the state machine * @work: work_struct that describes the work to be done */ void phy_state_machine(struct work_struct *work) { struct delayed_work *dwork = to_delayed_work(work); struct phy_device *phydev = container_of(dwork, struct phy_device, state_queue); bool needs_aneg = false, do_suspend = false; enum phy_state old_state; int err = 0; int old_link; mutex_lock(&phydev->lock); old_state = phydev->state; if (phydev->drv->link_change_notify) phydev->drv->link_change_notify(phydev); switch (phydev->state) { case PHY_DOWN: case PHY_STARTING: case PHY_READY: case PHY_PENDING: break; case PHY_UP: needs_aneg = true; phydev->link_timeout = PHY_AN_TIMEOUT; break; case PHY_AN: err = phy_read_status(phydev); if (err < 0) break; /* If the link is down, give up on negotiation for now */ if (!phydev->link) { phydev->state = PHY_NOLINK; netif_carrier_off(phydev->attached_dev); phydev->adjust_link(phydev->attached_dev); break; } /* Check if negotiation is done. Break if there's an error */ err = phy_aneg_done(phydev); if (err < 0) break; /* If AN is done, we're running */ if (err > 0) { phydev->state = PHY_RUNNING; netif_carrier_on(phydev->attached_dev); phydev->adjust_link(phydev->attached_dev); } else if (0 == phydev->link_timeout--) needs_aneg = true; break; case PHY_NOLINK: if (phy_interrupt_is_valid(phydev)) break; err = phy_read_status(phydev); if (err) break; if (phydev->link) { if (AUTONEG_ENABLE == phydev->autoneg) { err = phy_aneg_done(phydev); if (err < 0) break; if (!err) { phydev->state = PHY_AN; phydev->link_timeout = PHY_AN_TIMEOUT; break; } } phydev->state = PHY_RUNNING; netif_carrier_on(phydev->attached_dev); phydev->adjust_link(phydev->attached_dev); } break; case PHY_FORCING: err = genphy_update_link(phydev); if (err) break; if (phydev->link) { phydev->state = PHY_RUNNING; netif_carrier_on(phydev->attached_dev); } else { if (0 == phydev->link_timeout--) needs_aneg = true; } phydev->adjust_link(phydev->attached_dev); break; case PHY_RUNNING: /* Only register a CHANGE if we are polling or ignoring * interrupts and link changed since latest checking. */ if (!phy_interrupt_is_valid(phydev)) { old_link = phydev->link; err = phy_read_status(phydev); if (err) break; if (old_link != phydev->link) phydev->state = PHY_CHANGELINK; } /* * Failsafe: check that nobody set phydev->link=0 between two * poll cycles, otherwise we won't leave RUNNING state as long * as link remains down. */ if (!phydev->link && phydev->state == PHY_RUNNING) { phydev->state = PHY_CHANGELINK; dev_err(&phydev->dev, "no link in PHY_RUNNINGn"); } break; case PHY_CHANGELINK: err = phy_read_status(phydev); if (err) break; if (phydev->link) { phydev->state = PHY_RUNNING; netif_carrier_on(phydev->attached_dev); } else { phydev->state = PHY_NOLINK; netif_carrier_off(phydev->attached_dev); } phydev->adjust_link(phydev->attached_dev); if (phy_interrupt_is_valid(phydev)) err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED); break; case PHY_HALTED: if (phydev->link) { phydev->link = 0; netif_carrier_off(phydev->attached_dev); phydev->adjust_link(phydev->attached_dev); do_suspend = true; } break; case PHY_RESUMING: if (AUTONEG_ENABLE == phydev->autoneg) { err = phy_aneg_done(phydev); if (err < 0) break; /* err > 0 if AN is done. * Otherwise, it's 0, and we're still waiting for AN */ if (err > 0) { err = phy_read_status(phydev); if (err) break; if (phydev->link) { phydev->state = PHY_RUNNING; netif_carrier_on(phydev->attached_dev); } else { phydev->state = PHY_NOLINK; } phydev->adjust_link(phydev->attached_dev); } else { phydev->state = PHY_AN; phydev->link_timeout = PHY_AN_TIMEOUT; } } else { err = phy_read_status(phydev); if (err) break; if (phydev->link) { phydev->state = PHY_RUNNING; netif_carrier_on(phydev->attached_dev); } else { phydev->state = PHY_NOLINK; } phydev->adjust_link(phydev->attached_dev); } break; } mutex_unlock(&phydev->lock); if (needs_aneg) err = phy_start_aneg(phydev); else if (do_suspend) phy_suspend(phydev); if (err < 0) phy_error(phydev); dev_dbg(&phydev->dev, "PHY state change %s -> %sn", phy_state_to_str(old_state), phy_state_to_str(phydev->state)); queue_delayed_work(system_power_efficient_wq, &phydev->state_queue, PHY_STATE_TIME * HZ); } 
