[U-Boot] [PATCH 1/1] dwc2 USB controller hangs with lan78xx

[Alexander Graf]

On 06/21/2018 10:37 AM, Peter Robinson wrote:
> On Mon, Jun 18, 2018 at 7:56 PM, Andrew Thomas <andrew.thomas at oracle.com> wrote:
>> This bug is the combination of dwc2 USB controller and lan78xx
>> USB ethernet controller, which is the combination in use on
>> the Raspberry Pi Model 3 B+.
>>
>> When the host attempts to receive a packet, but a packet has not
>> arrived, the lan78xx controller responds by setting BIR
>> (Bulk-In Empty Response) to NAK. Unfortunately, this hangs
>> the USB controller and requires the USB controller to
>> be reset.
>>
>> The fix proposed is to have the lan78xx controller respond
>> by setting BIR to ZLP.
>>
>> Signed-off-by: Andrew Thomas <andrew.thomas at oracle.com>
> Tested-by: Peter Robinson <pbrobinson at gmail.com>
>
> Tested on the RPi 3B+ and certainly improves this situation a number
> of Fedora users have seen.


What exactly have you tested?

Even with this patch, I am not reliably to reliably boot into grub. It 
almost seems as if the packet buffer keeps getting overwritten by newer 
packets so that by the time we process the old ones, the ones we wanted 
to see are gone.


Alex