Messages in this thread | | | Subject | Re: [RFC] net: phy: read link status twice when phy_check_link_status() | From | Heiner Kallweit <> | Date | Tue, 30 Jul 2019 08:08:47 +0200 |
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On 30.07.2019 06:03, liuyonglong wrote: > > > On 2019/7/30 4:57, Heiner Kallweit wrote: >> On 29.07.2019 05:59, liuyonglong wrote: >>> >>> >>> On 2019/7/27 2:14, Heiner Kallweit wrote: >>>> On 26.07.2019 11:53, Yonglong Liu wrote: >>>>> According to the datasheet of Marvell phy and Realtek phy, the >>>>> copper link status should read twice, or it may get a fake link >>>>> up status, and cause up->down->up at the first time when link up. >>>>> This happens more oftem at Realtek phy. >>>>> >>>> This is not correct, there is no fake link up status. >>>> Read the comment in genphy_update_link, only link-down events >>>> are latched. Means if the first read returns link up, then there >>>> is no need for a second read. And in polling mode we don't do a >>>> second read because we want to detect also short link drops. >>>> >>>> It would be helpful if you could describe your actual problem >>>> and whether you use polling or interrupt mode. >>>> >>> >>> [ 44.498633] hns3 0000:bd:00.1 eth5: net open >>> [ 44.504273] hns3 0000:bd:00.1: reg=0x1, data=0x79ad -> called from phy_start_aneg >>> [ 44.532348] hns3 0000:bd:00.1: reg=0x1, data=0x798d -> called from phy_state_machine,update link. >> >> This should not happen. The PHY indicates link up w/o having aneg finished. >> >>> >>> According to the datasheet: >>> reg 1.5=0 now, means copper auto-negotiation not complete >>> reg 1.2=1 now, means link is up >>> >>> We can see that, when we read the link up, the auto-negotiation >>> is not complete yet, so the speed is invalid. >>> >>> I don't know why this happen, maybe this state is keep from bios? >>> Or we may do something else in the phy initialize to fix it? >>> And also confuse that why read twice can fix it? >>> >> I suppose that basically any delay would do. >> >>> [ 44.554063] hns3 0000:bd:00.1: invalid speed (-1) >>> [ 44.560412] hns3 0000:bd:00.1 eth5: failed to adjust link. >>> [ 45.194870] hns3 0000:bd:00.1 eth5: link up >>> [ 45.574095] hns3 0000:bd:00.1: phyid=3, reg=0x1, data=0x7989 >>> [ 46.150051] hns3 0000:bd:00.1 eth5: link down >>> [ 46.598074] hns3 0000:bd:00.1: phyid=3, reg=0x1, data=0x7989 >>> [ 47.622075] hns3 0000:bd:00.1: phyid=3, reg=0x1, data=0x79a9 >>> [ 48.646077] hns3 0000:bd:00.1: phyid=3, reg=0x1, data=0x79ad >>> [ 48.934050] hns3 0000:bd:00.1 eth5: link up >>> [ 49.702140] hns3 0000:bd:00.1: phyid=3, reg=0x1, data=0x79ad >>> >>>>> I add a fake status read, and can solve this problem. >>>>> >>>>> I also see that in genphy_update_link(), had delete the fake >>>>> read in polling mode, so I don't know whether my solution is >>>>> correct. >>>>> >> >> Can you test whether the following fixes the issue for you? >> Also it would be interesting which exact PHY models you tested >> and whether you built the respective PHY drivers or whether you >> rely on the genphy driver. Best use the second patch to get the >> needed info. It may make sense anyway to add the call to >> phy_attached_info() to the hns3 driver. >> > > [ 40.100716] RTL8211F Gigabit Ethernet mii-0000:bd:00.3:07: attached PHY driver [RTL8211F Gigabit Ethernet] (mii_bus:phy_addr=mii-0000:bd:00.3:07, irq=POLL) > [ 40.932133] hns3 0000:bd:00.3 eth7: net open > [ 40.932458] hns3 0000:bd:00.3: invalid speed (-1) > [ 40.932541] 8021q: adding VLAN 0 to HW filter on device eth7 > [ 40.937149] hns3 0000:bd:00.3 eth7: failed to adjust link. > > [ 40.662050] Generic PHY mii-0000:bd:00.2:05: attached PHY driver [Generic PHY] (mii_bus:phy_addr=mii-0000:bd:00.2:05, irq=POLL) > [ 41.563511] hns3 0000:bd:00.2 eth6: net open > [ 41.563853] hns3 0000:bd:00.2: invalid speed (-1) > [ 41.563943] 8021q: adding VLAN 0 to HW filter on device eth6 > [ 41.568578] IPv6: ADDRCONF(NETDEV_CHANGE): eth6: link becomes ready > [ 41.568898] hns3 0000:bd:00.2 eth6: failed to adjust link. > > I am using RTL8211F, but you can see that, both genphy driver and > RTL8211F driver have the same issue. > >> >> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c >> index 6b5cb87f3..fbecfe210 100644 >> --- a/drivers/net/phy/phy_device.c >> +++ b/drivers/net/phy/phy_device.c >> @@ -1807,7 +1807,8 @@ int genphy_read_status(struct phy_device *phydev) >> >> linkmode_zero(phydev->lp_advertising); >> >> - if (phydev->autoneg == AUTONEG_ENABLE && phydev->autoneg_complete) { >> + if (phydev->autoneg == AUTONEG_ENABLE && >> + (phydev->autoneg_complete || phydev->link)) { >> if (phydev->is_gigabit_capable) { >> lpagb = phy_read(phydev, MII_STAT1000); >> if (lpagb < 0) >> > > I have try this patch, have no effect. I suppose that at this time, > the autoneg actually not complete yet. > > Maybe the wrong phy state is passed from bios? Invalid speed just > happen at the first time when ethX up, after that, repeat the > ifconfig down/ifconfig up command can not see that again. > > So I think the bios should power off the phy(writing reg 1.11 to 1) > before it starts the OS? Or any other way to fix this in the OS? > To get a better idea of whats going on it would be good to see a full MDIO trace. Can you enable MDIO tracing via the following sysctl file /sys/kernel/debug/tracing/events/mdio/enable and provide the generated trace?
Due to polling mode each second entries will be generated, so you better stop network after the issue occurred.
> > >
Heiner
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