LXT972 FEC problem on MPC855

LXT972 FEC problem on MPC855

[Xiaogeng (Shawn) Jin]

Hi,

After running ppcboot on our board successfully (including the fast
ethernet LXT972), we have trouble on enabling FEC on linux kernel. The
problem is that we cannot send any packets through the network after the
kernel is booted. The ethernet looks OK during initialization according
to the printed messages. We are trying to locate the problem but haven't
found yet so far. Any hints on what caused such problem?

My configuration on kernel (linux-2.4.4-08-09 from DENX) is
              860T FEC Ethernet
              Use MDIO for PHY configuration
              Support LXT971 PHY

Thanks.

- Shawn.


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Re: LXT972 FEC problem on MPC855

[Xiaogeng (Shawn) Jin]

> After running ppcboot on our board successfully (including the fast
> ethernet LXT972), we have trouble on enabling FEC on linux kernel. The
> problem is that we cannot send any packets through the network after the
> kernel is booted. The ethernet looks OK during initialization according
> to the printed messages. We are trying to locate the problem but haven't
> found yet so far. Any hints on what caused such problem?

The booting messages are as follows,
-------------duing initialization-----------------------------
eth0: FEC ENET Version 0.2, FEC irq 9, MII irq 10, addr 00:06:17:01:02:00
eth0: Phy @ 0x0, type LXT971 (0x001378e2)
-------------duing initialization-----------------------------
-------------Stack init (I guess)-----------------------------
NET4: Linux TCP/IP 1.0 for NET4.0
IP Protocols: ICMP, UDP, TCP
IP: routing cache hash table of 512 buckets, 4Kbytes
TCP: Hash tables configured (established 4096 bind 4096)
eth0: config: auto-negotiation on, 100FDX, 100HDX, 10FDX, 10HDX.
IP-Config: Incomplete network configuration information.
NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
-------------Stack init (I guess)-----------------------------

Using FLUKE to test the ethernet interface, it looks OK. No problem is
reported. But we couldn't see any packets transmitted out by the
interface. Have you encountered such problem before? Any hints will be
greatly appreciated. Thanks a lot.

> My configuration on kernel (linux-2.4.4-08-09 from DENX) is
>              860T FEC Ethernet
>              Use MDIO for PHY configuration
>              Support LXT971 PHY

BTW, if I disable "Use MDIO for PHY configuration", after I ping an
address, it'll dump data in TX ring buffer. If those data will help to
diagnose the problem, I'll paste them later.

- Shawn.


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Re: LXT972 FEC problem on MPC855

[Wolfgang Denk]

In message <3D6A6D9D.20404@redswitch.com> you wrote:
>
> > After running ppcboot on our board successfully (including the fast
> > ethernet LXT972), we have trouble on enabling FEC on linux kernel. The
> > problem is that we cannot send any packets through the network after the
> > kernel is booted. The ethernet looks OK during initialization according
> > to the printed messages. We are trying to locate the problem but haven't
> > found yet so far. Any hints on what caused such problem?
...
> eth0: config: auto-negotiation on, 100FDX, 100HDX, 10FDX, 10HDX.
> IP-Config: Incomplete network configuration information.

You are passing bad/insufficient boot arguments to the Linux  kernel;
unfortunaltely you don;t show us this part of the boot messages, so I
cannot even guess what you're doing wrong.

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
Do not underestimate the value of print statements for debugging.

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Re: LXT972 FEC problem on MPC855

[Xiaogeng (Shawn) Jin]

>>eth0: config: auto-negotiation on, 100FDX, 100HDX, 10FDX, 10HDX.
>>IP-Config: Incomplete network configuration information.
>
> You are passing bad/insufficient boot arguments to the Linux  kernel;
> unfortunaltely you don;t show us this part of the boot messages, so I
> cannot even guess what you're doing wrong.
Well, if IP-Config is not complete, we can change the configuration
using 'ifconfig' after the kernel starts. I did that. And I noticed that
'eth0' can receive packets but cannot transmit any packets. Here is the
result of running ifconfig.

---------------------------once----------------------------------
#ifconfig
eth0      Link encap:Ethernet  HWaddr 00:06:17:01:02:00
           inet addr:192.168.5.24  Bcast:192.168.5.255  Mask:255.255.255.0
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:180 errors:0 dropped:0 overruns:0 frame:0
           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:100
           RX bytes:18110 (17.6 kb)  TX bytes:0 (0.0 b)
           Base address:0xe00
---------------------------once----------------------------------
---------------------------twice---------------------------------
#ifconfig
eth0      Link encap:Ethernet  HWaddr 00:06:17:01:02:00
           inet addr:192.168.5.24  Bcast:192.168.5.255  Mask:255.255.255.0
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:282 errors:0 dropped:0 overruns:0 frame:0
           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:100
           RX bytes:26831 (26.2 kb)  TX bytes:0 (0.0 b)
           Base address:0xe00
---------------------------twice---------------------------------

- Shawn.


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Re: LXT972 FEC problem on MPC855

[Ricardo Scop]

Shawn:

Maybe I have a contribution...

On Monday 26 August 2002 18:32, Xiaogeng (Shawn) Jin wrote:
> > You are passing bad/insufficient boot arguments to the Linux  kernel;
> > unfortunaltely you don;t show us this part of the boot messages, so I
> > cannot even guess what you're doing wrong.
>
> Finally I figured out the problem and solved it. The problem is that the
> kernel didn't get the LINK status correctly. The 'fep->link' was always
> 0 which means the link is down or autonegotiation is in progress.
>
> In the code which defines 'phy_info_lxt971', it says that somehow LXT971
> tells me that the link is down when the first read after power-up. So
> you have to read MII_REG_SR to set 'fep->phy_status' accordingly. But in
> my case, the read action occurred too early to wait till the link is up.
> So what I did is to delay 5s before reading MII_REG_SR during opening
> FEC device. I guess it takes the link a while to autonegotiate the speed.

Hmm. I suppose PHY should interrupt when link status change, and therefore
phy_status would be updated accordingly. So, maybe you have a problem with
your board's PHY interrupt signal.

Hope this helps.

-Scop.

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Re: LXT972 FEC problem on MPC855

[Xiaogeng (Shawn) Jin]

>>In the code which defines 'phy_info_lxt971', it says that somehow LXT971
>>tells me that the link is down when the first read after power-up. So
>>you have to read MII_REG_SR to set 'fep->phy_status' accordingly. But in
>>my case, the read action occurred too early to wait till the link is up.
>>So what I did is to delay 5s before reading MII_REG_SR during opening
>>FEC device. I guess it takes the link a while to autonegotiate the speed.
>
> Hmm. I suppose PHY should interrupt when link status change, and therefore
> phy_status would be updated accordingly. So, maybe you have a problem with
> your board's PHY interrupt signal.

Yeah, I think so. So I have to check whether the PHY interrupt is
enabled or not. Thanks for your thoughts.

- Shawn.


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