Network functionality in v2020.04 on Raspberry Pi 4

[Jevtic, Sasha]

Matthias,

I would be happy to do this, but unfortunately will not be able to until I can return to the laboratory where my setup resides.  This is likely still some weeks out due to significant COVID-19 activity in my region.  I am remote right now and only have power control and UART/Ethernet access to my RPi4s which have no cards installed.  If you or anyone else are able to support sooner, I would be very grateful.

Thanks.

Sasha

-----Original Message-----
From: Matthias Brugger <mbrugger at suse.com> 
Sent: Friday, April 17, 2020 2:19 PM
To: Jevtic, Sasha <sasha.jevtic at continental-corporation.com>; Harald Seiler <hws at denx.de>; u-boot at lists.denx.de; Andre Przywara <andre.przywara at arm.com>
Subject: Re: Network functionality in v2020.04 on Raspberry Pi 4

Hi Sasha,

On 4/17/20 9:15 PM, Jevtic, Sasha wrote:
> [Previous message to list canceled; resending with added detail]
> 
> Harald,
> 
> To be clear, the language I used was to imply *only* that I observed this problem as recently as the latest release; none over the earlier builds I have prepared for RPi4 worked better.  The reference to other hardware and older U-Boot was simply intended to suggest that the network infrastructure, notably including the DHCP and TFTP servers, have been proven to work with U-Boot.
> 
> Moreover, I would like to point out that I am chain loading U-Boot from the RPi4 firmware via TFTP.  This could be a significant point since the RPi4 firmware will have clearly already have initialized the Ethernet hardware previously.
> 

Could you try this with a u-boot booted from the SD card, so that we can see if the problem happens there as well?

Regards,
Matthias

> Thanks.
> 
> Sasha
> 
> -----Original Message-----
> From: Harald Seiler <hws at denx.de>
> Sent: Friday, April 17, 2020 4:12 AM
> To: Jevtic, Sasha <sasha.jevtic at continental-corporation.com>; 
> u-boot at lists.denx.de
> Cc: Matthias Brugger <mbrugger at suse.com>
> Subject: Re: Network functionality in v2020.04 on Raspberry Pi 4
> 
> Hello Sasha,
> 
> adding Matthias Brugger on Cc as he is the maintainer for Raspberry Pi.
> 
> On Thu, 2020-04-16 at 20:25 +0000, Jevtic, Sasha wrote:
>> Hello all,
>>
>> I am encountering considerable difficulty with the networking 
>> functionality on Raspberry Pi 4 on the latest release (2020.04).  In 
>> particular, I have observed:
>>
>>     * any network operation that fails renders networking functionality
>>       inoperable until reboot.
>>     * ping always fails.
>>     * TFTP download attempt of non-existent file fails (resulting in
>>       subsequent network operations failing).
>>     * TFTP download of an existing file usually works, but occasionally
>>       experiences timeouts during transfers; some are timeouts are
>>       intermittent (the transfer ultimately resumes), and some are
>>       permanent.
>>     * TFTP download of a script usually works (as above). The script
>>       will run, but any additional TFTP downloads performed by a script
>>       all fail.
>>
>> It is not entirely clear right now whether this is a problem in 
>> U-Boot (i.e., instead of in the execution environment set up by the 
>> Raspberry Pi firmware), but the TFTP infrastructure I am using is 
>> known to work well with other hardware running an older version of 
>> U-Boot.  Also, there are also no network issues in the Linux 
>> environment that I ultimately boot, so hardware also seems unlikely.  
>> Thus, suggestions for things to check would be appreciated; I am of 
>> course also happy to provide any supporting data required to investigate.
> 
> If you have know which older version still worked, you can use git-bisect [1] to find out where the regression was introduced.  Ideally, if you can automate installation of a newly built U-Boot version, this can run entirely unattended to find out where the bug was introduced.
> 
> [1]: https://git-scm.com/docs/git-bisect
> 
>> Please also be aware that I initially posted a very similar inquiry 
>> to the Raspberry Pi Forum:
>>
>> https://www.raspberrypi.org/forums/viewtopic.php?f=29&t=271068
>>
>> Thanks.
>>
>> Sasha
> --
> Harald
>