[U-Boot-Users] SCC Ethernet and "Linux crashes by early packets" ???

[U-Boot-Users] SCC Ethernet and "Linux crashes by early packets" ???

[Steven Scholz]

Hi there,

the CHANGELOG contains the lines

* Make sure SCC Ethernet is always stopped by the time we boot Linux
   to avoid Linux crashes by early packets coming in.

in "Changes for U-Boot 1.0.2".

My two question:

1.) How can I find out which changes in the CVS do excactly this?
2.) Do we need the same with 8xx FEC Ethernet?

I am asking because I am expierencing sporadic crashes when booting linux 
from U-Boot 1.0.0. But only when I init the ethernet (e.g. by doing "dhcp" 
or "tftp") before booting...

-- 
Steven Scholz

imc Measurement & Control               imc Me?systeme GmbH
Voltastr. 5                             Voltastr. 5
13355 Berlin                            13355 Berlin
Germany                                 Deutschland

[U-Boot-Users] SCC Ethernet and "Linux crashes by early packets" ???

[Wolfgang Denk]

In message <40757661.50905@imc-berlin.de> you wrote:
> 
> the CHANGELOG contains the lines
> 
> * Make sure SCC Ethernet is always stopped by the time we boot Linux
>    to avoid Linux crashes by early packets coming in.
> 
> in "Changes for U-Boot 1.0.2".
> 
> My two question:
> 
> 1.) How can I find out which changes in the CVS do excactly this?

Checking the CVS logs?

Try: cvs diff -r1.3 -r1.4 post/ether.c 

> 2.) Do we need the same with 8xx FEC Ethernet?

I don't think so. Note that the ethernet interface was left in a non-
stopped state by the POST code.  Normal  network  use  will  (should)
correctly shut down the interface.


Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
Prediction is very difficult, especially of the future.  - Niels Bohr

[U-Boot-Users] SCC Ethernet and "Linux crashes by early packets" ???

[Steven Scholz]

Wolfgang Denk wrote:

> In message <40757661.50905@imc-berlin.de> you wrote:
> 
>>the CHANGELOG contains the lines
>>
>>* Make sure SCC Ethernet is always stopped by the time we boot Linux
>>   to avoid Linux crashes by early packets coming in.
>>
>>in "Changes for U-Boot 1.0.2".
>>
>>My two question:
>>
>>1.) How can I find out which changes in the CVS do excactly this?
> 
> Checking the CVS logs?

Maybe I am to stupid. Of course I can find the line

"Make sure SCC Ethernet is always stopped by the time we boot Linux"

in the CVS logs. Actually it's there 128 times.
But I could not find out which file excactly was changed for this purpose!

 > Try: cvs diff -r1.3 -r1.4 post/ether.c
And I never thought of POST code!
Thanks!

>>2.) Do we need the same with 8xx FEC Ethernet?
> 
> 
> I don't think so. Note that the ethernet interface was left in a non-
> stopped state by the POST code.  Normal  network  use  will  (should)
> correctly shut down the interface.

Hmm. Then I have another problem and start a new thread.

Thanks.

Steven

[U-Boot-Users] SCC Ethernet and "Linux crashes by early packets" ???

[Wolfgang Denk]

In message <407674A7.7040805@imc-berlin.de> you wrote:
> 
> > Checking the CVS logs?
> 
> Maybe I am to stupid. Of course I can find the line
> 
> "Make sure SCC Ethernet is always stopped by the time we boot Linux"
> 
> in the CVS logs. Actually it's there 128 times.
> But I could not find out which file excactly was changed for this purpose!

Yes, I know; some other files were also changed during this  checkin.
Buit  if  you look at the patchset, it seems obvious to me that there
was only one netweork related source file included.  [You  are  using
cvsps, aren't you?]

>  > Try: cvs diff -r1.3 -r1.4 post/ether.c
> And I never thought of POST code!

So did we [not]. Don't ask how loong  it  took  to  trace  down  this
problem,  which  apperared  just  for one customer, and just in their
network environment [with a lot of windoze broadcasts], and never  in
our lab [which is 100% Micro$oft-free].

> Hmm. Then I have another problem and start a new thread.

Good luck. May your pesticide be efficient ;-)

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
Microsoft Multitasking:
                     several applications can crash at the same time.

[U-Boot-Users] SCC Ethernet and "Linux crashes by early packets" ???

[Pantelis Antoniou]

Wolfgang Denk wrote:

>In message <40757661.50905@imc-berlin.de> you wrote:
>
>>the CHANGELOG contains the lines
>>
>>* Make sure SCC Ethernet is always stopped by the time we boot Linux
>>   to avoid Linux crashes by early packets coming in.
>>
>>in "Changes for U-Boot 1.0.2".
>>
>>My two question:
>>
>>1.) How can I find out which changes in the CVS do excactly this?
>>
>
>Checking the CVS logs?
>
>Try: cvs diff -r1.3 -r1.4 post/ether.c 
>
>
>>2.) Do we need the same with 8xx FEC Ethernet?
>>
>
>I don't think so. Note that the ethernet interface was left in a non-
>stopped state by the POST code.  Normal  network  use  will  (should)
>correctly shut down the interface.
>
>
>
Actually we most certainly do. I was bitten by the same bug the past
week and have a patch ready; I'm just waiting for my other patches to
be included in order to sent it.

When we leave any ethernet on with DMA capability, there is a small
window of time before the new code reprograms the controller and stops
the DMA.

In the mean time if a packet is received (typically a broadcast) it
will write over in the physical memory where u-boot had placed it's
buffers. It's a crapshoot. Most of the times no-one will notice
since the possibility of actually overwritting something important is
very small.


>Best regards,
>
>Wolfgang Denk
>
>
Regards

Pantelis

[U-Boot-Users] SCC Ethernet and "Linux crashes by early packets" ???

[Steven Scholz]

Pantelis Antoniou wrote:

>> I don't think so. Note that the ethernet interface was left in a non-
>> stopped state by the POST code.  Normal  network  use  will  (should)
>> correctly shut down the interface.
>>
> Actually we most certainly do. I was bitten by the same bug the past
> week and have a patch ready; I'm just waiting for my other patches to
> be included in order to sent it.

Maybe you want to send this patch to me. So I could test if this fixes 
things for me as well?

Thanks!



-- 
Steven Scholz

imc Measurement & Control               imc Me?systeme GmbH
Voltastr. 5                             Voltastr. 5
13355 Berlin                            13355 Berlin
Germany                                 Deutschland