[U-Boot] [PATCH] net: asix: Fix ASIX 88772B with driver model

[Marek Vasut]

On 08/09/2016 02:14 PM, Marcel Ziswiler wrote:
> On Thu, 2016-08-04 at 11:12 +0200, Marek Vasut wrote:
>> On 08/04/2016 11:07 AM, Alban Bedel wrote:
>>>
>>> On Wed, 3 Aug 2016 15:23:30 +0000
>>> Marcel Ziswiler <marcel.ziswiler at toradex.com> wrote:
>>>
>>>>
>>>> On Wed, 2016-08-03 at 15:51 +0200, Marek Vasut wrote:
>>>>>
>>>>> On 08/03/2016 11:46 AM, Alban Bedel wrote:
>>>>>>
>>>>>>
>>>>>> On Wed, 3 Aug 2016 09:00:42 +0200
>>>>>> Marek Vasut <marex at denx.de> wrote:
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On 08/03/2016 07:32 AM, Alban Bedel wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>> Commit 147271209a9d ("net: asix: fix operation without
>>>>>>>> eeprom")
>>>>>>>> added a special handling for ASIX 88772B that enable
>>>>>>>> another
>>>>>>>> type of header. This break the driver in DM mode as the
>>>>>>>> extra
>>>>>>>> handling
>>>>>>>> needed in the receive path is missing.
>>>>>>> So add the extra handling ?
>>>>>> I can do that too, but I though u-boot preferred to avoid
>>>>>> useless
>>>>>> code.
>>>>> Yes, if it is useless.
>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> However this new header mode is not required and only
>>>>>>>> seems to
>>>>>>>> increase the code complexity, so this patch revert this
>>>>>>>> part of
>>>>>>>> commit 147271209a9d.
>>>>>>> Why is it not required ?
>>>>>> It works fine without, since 2012. In fact this change is not
>>>>>> even
>>>>>> mentioned in the log of commit 147271209a9d, so I really
>>>>>> don't know
>>>>>> why
>>>>>> it was added in the first place. As can be seen in the revert
>>>>>> all
>>>>>> it
>>>>>> does is adding 2 bytes to the USB packets that are then just
>>>>>> skipped.
>>>>>> Seems pretty useless to me.
>>>>> I would like to get some feedback on this from Marcel, since he
>>>>> added
>>>>> this stuff.
>>>> Yes, sorry. I just came back from vacation and started looking
>>>> into it
>>>> now. As far as I remember on our hardware without this Ethernet
>>>> did not
>>>> quite work reliably. This also means that with driver model so
>>>> far it
>>>> does not work for us which I fed back to Simon once but so far
>>>> this has
>>>> not been resolved. That fix came from some early U-Boot work done
>>>> by
>>>> Antmicro way back and I am missing some of the history.
>>> Then I'll do a new patch that just fix the driver model receive
>>> path.
>> Hold on. Marcel, can you maybe test if removing this code has any
>> impact
>> on the behavior now ?
> 
> Sorry for the delay. I tested Alban's patch now both on Toradex Colibri
> T20 as well as T30 and its on-module ASIX USB-to-Ethernet chip actually
> works perfectly aside from the occasional EHCI timed out on TD -
> token=0x88008d80 Rx: failed to receive: -5 message which last I checked
> with Simon is still unresolved but was already there long before any of
> the driver model work started.
> 
> Tested-by: Marcel Ziswiler <marcel.ziswiler at toradex.com>
> Tested-on: Colibri T20/T30 on Colibri Evaluation Board
> 
Thanks!

-- 
Best regards,
Marek Vasut