Linux/AM5728: DP83822HF FX Mode problem.

Yohan Kim

Expert 1385 points

Part Number: AM5728
Other Parts Discussed in Thread: DP83822HF, DP83849IF,

Tool/software: Linux

Hi.

I'm using AM572x custom board

and, DP 83822HF is connected to RPU2 ETH0/ETH1

DP83822HF Phy chip is used in two Fx modes.
But there is a problem.

The problem is that two ports can not communicate at the same time.

1. B port is not used when A port is used, and there is no reverse case.
2. If you disconnect the A port and connect to the B port, communication can not be performed.

this is phy chip regster log

==== DP83822HF_config_intr 246===
BMCR(0x0): 0x2100
BMSR(0x1): 0x784d
BMSR(0x1): 0x784d
PHYIDR1(0x2): 0x2000
PHYIDR2(0x3): 0xa240
CR1(0x9): 0x0
CR2(0xa): 0x4100
FLDSTS(0xF): 0x0
PHYSTS(0x10): 0x205
PHYSCR(0x11): 0x109
RCSR(0x17): 0x41
LEDCR(0x18): 0x400
PHYCR(0x19): 0x21
GENCFG(0x465): 0xff00
=================

this is schematic

Best Regards,

John Kim

over 8 years ago

0 Yohan Kim over 8 years ago

Expert 1385 points

I found a new thing.
In FX-mode, Flow control is off as shown below.
"Eth 2: Link is Up - 100 Mbps / Full - flow control off"
"Eth 3: Link is Up - 100 Mbps / Full - flow control off"

However, in TX-mode, Flow control is On as shown below.
"Eth 2: Link is Up - 100 Mbps / Full - flow control rx / tx"
"Eth 3: Link is Up - 100 Mbps / Full - flow control rx / tx"

So I used "ethtool" to forcibly turn on flow control,
However, when setting it using "ethtool", an error occurs as follows.
"# Ethtool-A eth3 rx on tx on
Can not get device pause settings: Operation not supported "

Why is Flow control off in FX-mode? "
Is there a way to turn Flow control on in FX-mode?

Best Regards,
John Kim

0 Yordan Kovachev over 8 years ago in reply to Yohan Kim

TI__Guru**** 161600 points

Hi,

We're looking into this. Feedback will be posted here.

Best Regards,
Yordan

0 Yohan Kim over 8 years ago in reply to Yordan Kovachev

Expert 1385 points

Hi, Yordan.

We found the same problem in other Phy chip DP83849IF used in FX Mode.

Best Regards,
John Kim

0 Yordan Kovachev over 8 years ago in reply to Yohan Kim

TI__Guru**** 161600 points

Hi,

Sorry for the late reply.

Are you enabling both eth ports first, as described here:
processors.wiki.ti.com/.../PRU-ICSS_Ethernet

Can you share your dts?

Best Regards,
Yordan

0 Yohan Kim over 8 years ago in reply to Yordan Kovachev

Expert 1385 points

Hi, Yordan

I am using the default DTS settings of the AM5728.
The DP83822HF is defined and in use in the DP83848.c file.

I tryed dual mac bonding connection.
the problem was not solved.

# Ethernet Binding
ifconfig eth2 down;
ifconfig eth3 down;
echo 1 > /sys/class/net/bond0/bonding/mode;
echo 100 > /sys/class/net/bond0/bonding/miimon;
ifconfig bond0 192.168.0.100 netmask 255.255.254.0 up;
echo +eth2 > /sys/class/net/bond0/bonding/slaves;
echo +eth3 > /sys/class/net/bond0/bonding/slaves;

Best Regards,
John Kim

0 Yohan Kim over 8 years ago in reply to Yordan Kovachev

Expert 1385 points

I was posting the same issue on the Ethernet Forum, but the problem was not resolved.

I was informed by the forum to contact the Linux Driver team.

e2e.ti.com/.../617314

Best Regards,
John Kim

0 Yohan Kim over 8 years ago in reply to Yordan Kovachev

Expert 1385 points

Hi,

I have found the cause of the link up / drop problem.

In the case of FX mode with "phy_state_machine" function of phy.c code
Problem that does not read Phy chip state by "phy_interrupt_is_valid" function
visited.

In this code, "phy_interrupt_is_valid" function If you delete the part to check,
It will judge Link Up / Drop well.

in phy.c

-------------------------------------------------------------------------------------------------------------------------------------

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_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;
//}
break;

-------------------------------------------------------------------------------------------------------------------------------------

I suspect DP83822HF related driver code problem.

Best Regards,
John Kim

0 Yordan Kovachev over 8 years ago in reply to Yohan Kim

TI__Guru**** 161600 points

Hi,

Thanks for sharing your solution.

Best Regards,
Yordan

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Linux/AM5728: DP83822HF FX Mode problem.